USF Libraries
USF Digital Collections

Analysis and assessment of the 1990 nationwide personal transportation study in relation to travel characteristics in th...


Material Information

Analysis and assessment of the 1990 nationwide personal transportation study in relation to travel characteristics in the United States and Florida
Physical Description:
xii, 140 p. : ill. ; 28 cm.
Rey, Joel R
Publication Date:


Subjects / Keywords:
Traffic surveys -- Florida   ( lcsh )
1990 Nationwide Personal Transportation Study   ( lcsh )
Transportation, Automotive -- Florida   ( lcsh )
Traffics Surveys -- United States   ( lcsh )
Transportation, Automotive -- United States   ( lcsh )
Dissertations, Academic -- Civil engineering -- Masters -- USF   ( lcsh )
bibliography   ( marcgt )
non-fiction   ( marcgt )


Thesis (M.S.C.E.)--University of South Florida, 1992.
Includes bibliographical references (p. 93-96).
Additional Physical Form:
Also available online.
Statement of Responsibility:
by Joel R. Rey.

Record Information

Source Institution:
University of South Florida Library
Holding Location:
University of South Florida
Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 029043319
oclc - 27192434
usfldc doi - C01-00305
usfldc handle - c1.305
System ID:

This item is only available as the following downloads:

Full Text
xml version 1.0 encoding UTF-8 standalone no
record xmlns http:www.loc.govMARC21slim xmlns:xsi http:www.w3.org2001XMLSchema-instance xsi:schemaLocation http:www.loc.govstandardsmarcxmlschemaMARC21slim.xsd
leader nam 2200277Ia 4500
controlfield tag 001 029043319
005 20090126081655.0
008 930104s1992 xx a b 000|0 eng d
datafield ind1 8 ind2 024
subfield code a C01-00305
1 100
Rey, Joel R.
0 245
Analysis and assessment of the 1990 nationwide personal transportation study in relation to travel characteristics in the United States and Florida /
by Joel R. Rey.
xii, 140 p. :
b ill. ;
28 cm.
Thesis (M.S.C.E.)--University of South Florida, 1992.
Includes bibliographical references (p. 93-96).
Also available online.
Traffic surveys
z Florida.
1990 Nationwide Personal Transportation Study.
Transportation, Automotive
Traffics Surveys
United States.
Transportation, Automotive
United States.
Dissertations, Academic
x Civil engineering
t Center for Urban Transportation Research Publications [USF].
4 856


ANALYSIS AND ASSESSMENT OF THE 1990 NATIONWIDE PERSONAL TRANSPORTATION STUDY IN RELATION TO TRAVEL CHARACTERISTICS IN THE UNITED STATES AND FLORIDA by Joel R. Ray A thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Civil Engineering in the Department of Civil Engineering in the University of South Aorida August 1992 Major Professor: Steven E. Polzin, Ph.D.


ACKNOWLEDGEMENTS I would like to thank Dr. Steven E. Polzin of the Center for Urban Transportation Research (CUTR), my major professor, for his guidance and the knowledge and assistance that he provided during the writing of this thesis; and Mr. Gary L. Brosch, director of CUTR for giving me the opportunity to work at this unique 0 research center. In addition, I would like to thank Dr. Alan R Kaub and Dr. Lee A. Weaver, who served on my committee, for their reviews of this thesis. I would also like to thank Susan Uss at the Office of Highway Information Management, Federal Highway Admin i stration, U S Department of Transportation, for her interest in my work and her assistance w it h the 1990 NPTS database and its analys i s. Special thanks go to my w i fe, Amy Sue, for her patience, understanding, and encouragement, and to my fam i ly for their support. Finalmente, muchos grac ias a mis abuelos. II





LIST OF TABLES Table 1. Regional Travel Household Surveys 15 Table 2. Comparison of NPTS Surveys 37 Table 3. NPTS Comparative Demographic and Travel Characteristics 44 Table 4. Average Househo l d Characterist ics 45 Table 5. United States Average Annual Household Travel By Househo l d Size and Vehic l e Availability 47 Table 6. FloridaAverage Annual Househo l d Travel By Household Siz e and Vehicle Availability 47 Table 7. Househo l d Income Characteristics 48 Table 8. Race and Hispanic Origin 50 Table 9. Distribution of Ucensed Dr i vers By Age and Gender 51 Table 10. Average Daily Vehicle Trips, Vehicle Miles, and Trip length By Age and Gender 53 Table 11. Average Daily Person T rips, Person Miles, and Trip Length By Age and Gender 55 Table 12. Total Travel By Income Category 56 Table 13. Person Trips By Household Location 57 Table 14. Distribution of Work Commute Trips By Usual Mode 58 Table 15. Summary of Annual Household Veh icle Trip Data By Purpose 60 v


Table 16. United States Vehicle Trips By Purpose and Trip Distance 62 Table 17. Florida Vehicle Trips By Purpose and Trip Distance Table 18 Vehicle Occupancy By Purpose and Mode Table 19. United States Person Trip Distribution By Purpose and 62 63 Table 20. Florida Person Trip Disbibution By Purpose and Mode 65 Table 21. United States Average Person Trip Length By Purpose and Mode 67 Table 22. Aorlda Average Person Trip Length By Purpose and Mode 67 Table 23. United States Average Person Trip Travel T i me By Purpose and Mode 68 Table 24. Aorida. Average P11rson Tr ip Travel Time By Purpose and Mode 68 Table 25. 1969 1977, 1983, and 1990 NPTS, Comparative Statistics 70 Table 26. 1969, 1977, 1983, and 1990 NPTS, Average Household Demographic and Travel Characteristics 72 Table 27. 1969, 1977, 1983, and 1990 NPTS, Household Vehicle Availability 73 Table 28. 1969, 1977, 1983, and 1990 NPTS, Average Annual Household Vehicle Trip Data By Purpose 74 Table 29. 1969, 1977, 1983, and 1990 NPTS, Average Vehicle Occupancy By Purpose 75 Table 30. 1969, 1977, 1983, and 1990 NPTS Disbibution of Work Commute Trips By Mode 76 vi


.. Table 31. 1969, 1977, 1983, and 1990 NPTS, Annual Person Trips (Millions) By Mode 77 Table 32. 1990 NPTS and Peers, Comparative Statistics 79 Table 33. 1990 NPTS and Peers, Average Household Demographic and Travel Characieristics 82 Table 34. 1990 NPTS and Peers, Household Vehicle Availability 83 vii


LIST OF FIGURES Figure 1 Distribution of the U.S. population (millions) Figure 2 National trends of demographic characteristics (mill ions). Figure 3 Changing road supply and travel demand i n the U.S., 23 23 percent change 1960-89. 25 Figure 4. D i stribution of the U.S. civilian l abor force (milli ons) 25 Figure 5. Distribution of the U.S. population by age (millions). 25 Figure 6 Vehicle miles of travel (VMT) in the U.S. (billions). 27 F i gure 7 Percent distr i bution of the number of household vehicles availab l e in the U.S. 27 F i gure 8 U S Journey to work moda l shares 27 Figure 9 Percent d i stribution of Florida and U S population between metropolitan and non-metropolitan areas, 1990. 29 Figure 10. Florida trends of demographic characteristics (millions). 29 Figure 11. Chang i ng road supply and travel demand in Flo r ida, percent change 197Q-89. 29 Figure 12 Trend in Florida s civilian labor force and employees (millions) 29 Figure 1 3 Distribution of Florida population by age (millions). 31 Figure 14. Percent distribution of the number of household vehicles available in Florida and the U.S. 3 1 Figure 1 5 Florida and U S Journey to wo r k modal shares, 1990. 31 vii i


AHS CATI CFRDC CUTR EIA FHWA FRA FTA HUD IS TEA MPO MSA MTA MTC MVMA NHTSA NPTS OST ROD RECS RTECS RTI SAS TBI TAB UMTA USDOT VMT UST OF ABBREVIATIONS American Housing Survey Computer-Assisted Telephone Interview Central Florida Regional Data Center Center for Urban Transportation Research En e rgy Information Administration Federal Highway Administration Federal Railroad Administration Federal Transit Administration (formerly U MTA) Department of Housing And Urban Development intermodal Surface Transportation Efficiency Act Metropolitan Planning Organization Metropolitan Statistical Area Metropolitan Transportation Authority (New York) Metropolitan Transportation Commission (San Francisco) Motor Vehicle Manufacturers Association National Highway Traffic Safety Administration Nationwide Personal Transportation Study Office of the Secretary of Transportation Random Digit Dialing Residential Energy Consumption Survey Residential Transportation Energy Consumption Survey Research Triangle Institute Statistical Analysis System Travel Behavior Inventory Transportation Research Board Urban Mass Transportation Administration (now FTA) U.S. Department of Transportation Vehicle Miles of Travel ix


ANALYSIS AND ASSESSMENT OF THE 1990 NATIONWIDE PERSONAL TRANSPORTATION STUDY IN RELATION TO TRAVEL CHARACTERISTICS IN THE UNITED STATES AND FLORIDA by Joel R. Rey AN ABSTRACT of a thesis submitted in partial fulfillment of the requirements for the degree of Master of Science in Civil Eng ineering in the Department of Civil Engineering in the University of South Florida August 1992 Major Professor: Steven E. Polzin, Ph.D. X


, . . Substantia l changes in travel behavior and urban development have taken plaoe over the last several years which have altered national travel characteristics and commuting patterns. These changes have increased demands on the nation's already strained transportation system and increased the desire for reliable, up-to-. date transportation information and knowledge of travel behavior. On a national level, the U.S. Department of Transportation and the Federal Highway Administra tion have collected new travel data via the 1990 Nationwide Personal Transportatlon Study (NPTS). Utilizing the 1990 NPTS data, this study investigated current travel behavior and demographics for the United States and Florida. Analyses i ncluded a comparison of F l orida travel and demographic characteristics to those of the nation to identify any potential differences and their underlying causes A comparison of the 1990 NPTS results to previous years NPTS results was conducted to highlight the changes that have occurred over the last twenty years; a comparison of the 1990 NPTS results to other current data and trends was also conducted to assess the consistency with this peer information The primary purpose of these analyses was to enhance the understanding of current travel behavior. In analyzing the data. several differences in socio-economic and travel characteris tics between Aorida and the nation were i dentified. Interesting findings incl uded xi


the lower utiliza t ion of transit, the shorter vehide trip lengths and the lo wer vehide occupancies fo r households in F lorida. The trend analysis showed that the NPTS data reflected acknow l edged demographic trends and captured known cha nges such as increasing fem ale participation in the work force, the aging of the population, the decreasing average size of households, and the increasing availabi lity of vehicles to household members. Similarly, the peer comparison analysis showed that, for the most part, the 1990 NPTS data approximated the peer data reasonably well. The 1990 NPTS survey data was useful in providing a better understanding of current travel behavior and demograph i c characteristic;:s. This knowledge is important to decisionmakers who must make informed choices when evaluating alternative t ransportation services and investments and related policy choices. This knowled ge of travel behavior is also helpful to transportation professionals for travel demand modeling, transportation demand management planning, land use planning transit service planning and rel ated tran sportation studies Abstract Approved: Major Professor: Steyen E. Polzin, Ph.D Deputy Director lor PofiCy Anatysjs, CUm Date of Approval xii


1 INTR O D UCT I O N The focus of this thesis is the analysis of the 1 Nationwide Personal Transporta tion Study (NPTS) with respect to current demographics and travel behavior. Analyses include a comparison of Florida demographics and travel characteristics to those of the nation, a comparison of the 1990 NPTS results to previous years NPTS results, and a comparison of the 1990 NPTS results to other current peer data and trends The primary purpose for these analyses is to gain a better understand ing of current travel behavior. Substantial changes In travel behavior and urban development have taken place over the last several decades. At the center of these changes Is the evolution of society-an evolution that has brought about new social values and norms, changes in the economy, advancements I n te chnology, and shifts In the locations of households and firms (Prevedouros & Scholer, 1989). Many of these changes have occurred rapidly, not allowing the transportation infrastructure to keep pace. Accelerated growth In the suburbs, the influx of women into the labor force, and increasing vehide ownership are but a few of the factors that have altered national travel characteristics and commuting patterns ( P isarski, 1987), thereby adding to the demands on the nation's already strained metropolitan roadway system.


2 As these demands for highway and services grow, so does the need for reliable, up-to-date transportation information and knowledge of travel behavior . Policy planning and analysis benefit from the existence of current knowledge about travel behavior; decisionmakers rely heavily on knowledge of behavior to make informed choices when evaluating alternative transportation services and investments and related land use plans. A current, comprehenslve data base of travel characteristics and socio-economic data is indispensable when attempting to forecast future transportation needs or develop accurate travel demand models Since many of the regional data bases which have been used extensively during the past decades are becoming outdated, there has been a recent push by many metropolitan planning organizations (MPOs) around the country to update their obsolete travel surveys and studies. On a national level, the U.S. Department of Transportation and the Federal Highway Administration have also endeavored to collect new travel data, specifiC8lly via the Journey-to-Work portion of the 1990 Census and the 1990 NPTS Utilizing the 1990 NPTS data, this study investigates current national travel behavior as well as travel-related characteristics in Florida. Analyses of the data provide a better understanding of current transportation trends, knowledge that enhances decisionmaking on issues of policy. investment, and land use as they relate to transportation in our state and across the country. With the signing of the lntermodal Surface Transportation Efficiency Act (ISTEA) in December 1991 (a six


--3 year biD that authorizes approximately $155 billion in funding for innovative, . multimodal solutions to meet growing transportation demand in the U.S. in an environmentally-sound and economically-efficient way), the need for current data and well-founded decisions becomes even more important to ensure that this tun 1 ing is utilized effectively In addressing our transportation needs (USDOT, 1991). This knowledge is necessary to aid In the identification of problems and the development of creative solutions, while informed decisionmaking will facilitate implementation of the solutions. NPTS Survey < As defined by the Office of Highway Information MaAagement, Federal Highway Administration (FHWA), the NPTS is a national survey of trips and travel which provides the data needed at the Federal level to assess the relative use of various modes of travel and provides information on the characteristics of commuters and the trips that they take (FHWA, August 1991). The survey collects data on all trips, by all modes (except boat or ship), for all members of the surveyed household age 5 and older. Tr i p data are collected for both a 24-hour travel day and a two-week travel period (for reporting longer trips). The 1990 NPTS is the fourth survey of the series; previous surveys were completed in 1969, 1977, and 1983 The eariier surveys were conducted by the Bureau of the Census as personal home interviews. The 1990 version differs in that it was conducted by the Research Triangle Institute (RTI) using a computer-


4 assisted telephone interviewing (CATI) system. In addition, the data were collected over a full calendar year for this survey in order to ensure the representation of seasonal variations in travel. The 1990 study produced raw data from 22,317 households representing 48,385 persons and 149,456 travel day trips (one-way). The raw data were weighted using factors developed by RTI to expand the sample to national annual travel estimates. Among the travel data collected were number of vehicle trips, vehicle miles of travel, trip length, trip purpose, vehicle occupancy, and average annual miles per driver. Various household demographic data were also collected: household income, size of household, number of vehicles owned by household, and employment I nformation for working-age members. Background Research The 1990 NPTS survey has generated considerable interest. Because the last NPTS survey was completed in 1983 and most planners and resea rchers are still utilizing 1980 Census Journey-to-Work data since most of the 1990 data has yet to be released it is not surpris i ng that the fourth installment of th is transportation survey has been getting so much attention. Since the ear1y results were released in August of 1991, numerous citations have appeared in various printed media discussing travel trend highlights of the survey (The Urban Transportation Monitor, September 1991; Sham, October 1991; Land Use Digest, November 1991). A review of several research papers and articles revealed that not only are the


5 previous data being used and cited, but the 1990 NPTS data are also being . . : eagerly awaited to either update analyses or to. verify interim estimates of specific tr!\Vel characteristics (Lave, 1990; Gordon, Richardson, & Jun, 1991). In Commuting in America, Pisarski makes use of various NPTS data from the 1969, I 19n, and 1983 surveys to supplement Census data and to illustrate several trends in travel behavior. The commuting characteristics of men and women were compared using 1969 and 1983 data; data were also used to illustrate the time/distance characteristics of commuting. Other NPTS data cited were the trip purpose distribution of person trips, the change in transit ridership over time, and the change in work travel during peak hours. Lave makes use of NPTS data in his February 1990 paper, "Things Won't Get A Lot Worse: The Future of U.S. Traffic Congestion In the paper, Lave seeks to dispel the "fatalistic prophesies about Mure gridlock" by analyzing the structural shifts in the demographics of auto ownership and use He makes use of average VMT per vehicle data from the 1969, 1977, and 1983 surveys; average occupancy by trip purpose data from the 1983 survey; and average daily person-miles per person data from the 1983 survey to support his conclusion that auto ownership Is effectively saturated, thus historical VMT growth rates are not likely to continue. In the July 1990 paper, "Transportation Myths: Travel Behav ior, System Condition and Land Use, Hartgen looks at several widely-held perceptions that he attempts


6 to dispel as myths. Using 1983 NPTS data as well as data from several other sources, Hartgen determines that auto use is efficient and that travel increases have been caused primarily by i ncreases in population rather than wasteful behavior; that traffic problems are worse in the suburbs than in downtown areas; and that trip lengths and rates are not increasing, but in fact have declined. Gordon, Richardson, and Jun also make use of NPTS data in their 1991 article, "The Commuting Paradox, Evidence from the Top Twenty." The article describes the authors' belief that a commuting paradox exists since the common perception is that congestion has been getting worse in recent years, yet average commuting times have remained stable or decreased slightly. Work trip times, distances, and speeds from the 19n and 1983 surveys were used to illustrate this paradox. Data from the 1985 American Housing Survey were used to confirm the NPTS findings. Methodology of Analysis The primary goal of this thesis project is to analyze the results of the 1990 NPTS survey and use the findings to gain a better understanding of current travel behavior on a national level as well as on a statewide basis, specifically Florida There are a number of objectives associated with this analysis, includ ing an assessment of the comparability of Florida's demographics and travel characteris tics to the nation's, an assessment of the comparability of the 1990 NPTS results with respect to the previous years' NPTS survey resu lts, and an assessment of the comparability of the 1990 NPTS results with respect to other current data


7 bases/surveys and national demographic trends. Each of these objectives is intended to support the primary goal of gaining greater knowledge of travel behavior. The preliminary analysis of the NPTS data was conducted using the mainframe version of SAS (version 5.18) and utilized three of the procedures, or "procs as they are referred to In the program, available in SAS: Pro c Freq(uency), Proc Tabulate, and Proc Means. These procedures were used to produce response frequencies fo r basic demographic and travel data and cross-tabulations between related variables such as number of vehicles by household income, vehicle trips by mode of transportation and trip purpose, and average annual miles driven per driver by age and gender. Given the size of this data base it was not possible to analyze all of the variables in the framework of this thesis. Demographic characteristics that were examined at both a national and a state ( Aorida) level included age, gender, race, Hispanic origin, household income, household size, veh i cle ownership, licensed drivers, workers, and size .of urban area. Travel behavior characteristics that were examined included mode choice, trip purpose, person trips and miles, vehicle trips and miles, trip distance, trip duration, availability of and distance to public transit, segmented trips, and vehicle occupancy. It should be noted that some of these variables were only analyzed in the context of other related variables.


8 The analysis effort involved exploratory research rather than a trad i tional hypothesis/solution-type methodology. It entailed the review of established trends from previous travel data sources and travel behavior research, and expected demographic characteristics culled from Census data and other related informa tion. The analysis and assessment of the 1990 NPTS data, therefore, was undertaken within the context of this overall demographic and travel behavior framework. In an effort to fulfill the aforementioned objectives, the analysis of the data focused on three areas of investigation: ( 1) How do Florida travelers and travel behavior compare to national averages? (2) How has travel behavior changed over the past several years? (3) How do the findings for this NPTS survey compare with other recent surveys? The first analysis involved the comparison of selected Aorida demographics and travel characteristics to national results for the same characteristics. It was anticipated that some differences in travel behavior would be evidenced, given Florida's accelerated growth and distinctive demographic makeup Tourism and its supporting service industry, the older population, and comparatively low land densities may have some effect on current Aorlda travel behavior. Also, the high occurrence of suburban fringe development may have played a role in contributing to the expected higher-than-average trip-making characteristics and travel distances.


' 9 The second analysis involved the comparison of selected 1990 NPTS demographics and travel characteristics to results from the 1969, 1977, and 1983 surveys in order to identify any significant changes over time (trend analysis). Assuming that changes over time were not due to procedural changes in the survey methodologies, these N PTS-related trends woul d then provide a basis for comparison with other trend travel data to consistency over time. 1he third and final, analysis In the study involved the comparison of selected 1990 NPTS data with data from various "peer" surveys or other data sources such as the 1989 American Housing Survey, the 1988 Residential Transportation Energy Consumption Survey, and Highway Statistics 1989, among others. The primary reason f or this last analysis was to develop a basis by which to evaluate the findings of the 1990 NPTS survey and Investiga te the consistency of the travel data over time. In the context of these analyses, some current trends and demographics were also exami ned. Some items of interest inclu ded: congestion and its impact on commuting, the impact of increasing two-employee households on travel patterns the impact of suburban sprawl on average commuting trip lengths, and the impact of greater vehlde ownership on vehicle miles and person miles of travel. Orga n ization o f the Thesis Following this I ntroduction, Chapter 1, there are five additional chapters and three appendices. Chapter 2 includes a more In-depth discussion of current survey data and their use Various national and regional surveys and other data sources are.


10 presented and their findings discussed; brief descriptions of current travel and demographic trends are presented for both Aorida and t he nation Chapter 3 provides a more detailed presentation of the 1990 NPTS survey and the statistical analysis software that was used (SAS) to analyze the data base. Chapter 4 presents the results of the analyses for comparison between Aorida and the nation for demographic data and travel behavior characteristics in tabular form. Florida's comparability to national trends is discussed. Chapter 5 cons ists of the trend comparison of the 1990 NPTS resu l ts to previous years' results for selected national indicators and the comparison of the 1990 NPTS results to other current peer' surveys. Again, resu"s for the selected indicators are presented in tabular form. Finally, Chapter 6 provides a brief summary of the findings and discusses additional opportunities for ana l ysis of the data. The three appendices contain supplementary materials. Appendix A provides a copy of the survey instrument used by RTI to conduct the survey. Appendix B cons ists of a listing of the SAS analysis procedures performed on the data, specifically the cross tabulations developed using the frequency and tabulate procedures. Appendix C provides a glossary of terms used in this thesis as they relate to the NPTS survey.


11 TRAVEL DATA: SURVEYS, NEED, AND CURRENT TRENDS collection and analysis of data is a common, albeit important, endeavor to many disciplines and fields of study, especially to those in the field of transporta tion. To understand the dependence of transportation planners and researchers on socio-economic and travel data, one only need look at the abundance of sources for transportation-related data Fact books on highway, transit, railroad, and mobility statistics are produced annually by such agencies as the Federal Highway Administration, the American Public Transit Association, the Association of American Railroads, and the Institute for Transportation Engineers. These publications serve as popular sources for summary data and basic trends Other publicat i ons, such as the Eno Transportat i on Foundation's Transportation in America and Commuting in America, not only present data, but also lend interpretation to the trends and attempt to highlight the reasons behind them. One of the most important sources for demographic and travel data, however, is the survey. Review of Selected National and Regional Surveys From roadside vehicle classification counts to telephone or home intarviews surveys are a time-tested tool for gathering information about the many through sampling only a few. The majority of transportatiO!lSpecifiC surveys are conducted


12 on a region-by-region basis by various regional or metropolitan planning agencies. These agencies conduct surveys in an effort to update their old, and sometimes obsolete, data bases Since these agencies have traditionally been a major source of information for demographic and travel data for the areas that they serve, it is Imperative that they have access to the most current data available. In addition, the sponsors of various national surveys have also recognized the Importance of current travel data and have added or expanded their transportation elements as a result. One national survey that has provided important demographic and vehic l e ownership information is the American Housing Survey (AHS), performed for the Department of Housing and Urban Development (HUD). According to HUD, this biennial survey (conducted annually prior to 1984) provides information on the size and composition of the housing inventory, the characteristics of its occupants, and other housing inventory data. The data are based on a sample of approximately 49 900 housing units located throughout the United States. The AHS was conducted in 1991, but the most recent available data is from the 1989 survey (HUD, 1991) The Residential Transportation Energy Consumption Survey (RTECS} is another useful national survey. The RTECS is a subsample of the Residential Energy Consumption Survey (RECS), a triennial survey last conducted in 1988 by the Energy Info r mation Administration (EIA) to collect data on energy use in the


13 residential sector. Based on a sample of 2,986 housing units, the RTECS provides baseline lnfonnatlon on motor vehicle use in the residential sector. Detailed data are included for the number and type of vehicles, vehicle characteristics, total annual vehicle miles of travel (VMT), per household and per vehicle VMT, and vel:licle fuel consumption and expenditures (EIA, 1990). Two of the most comprehensive national transportation surveys are the Journey-to Work portion of the decennial Census and the Nationwide Personal Transportation Study (NPTS). The NPTS survey data Is exceptionally detailed; however, its scale of is not nearly as broad as the Journey-to-Work data. The 1990 NPTS will be discussed in greater detail in the next chapter. As for the Journey-to-Work element, what It lacks in detailed specifics is made up for by the comprehen siveness and unifonnity of its national data and the valuable source of fundamental work travel characteristics that it provides. The 1990 Journey-to-Work data include demographic information for persons, households, and workers as well as commute travel data such as trip mode, trip occupancy, trip departure time, trip duration, and worker travel patterns (FHWA, May 1992). Several national surveys have also been conducted to measure people's opinions, attitudes, and perceptions of important transportation-related issues. In 1989, Diversified Research, Inc., conducted a telephone interview survey of 4,000 persons in 17 metropolitan areas across the country who had access to public transportation lived within one-hal! mile). The survey was part of a study


14 completed by the Center for Urban Transportation Research (CU TR) for UMTA (now FTA) to identify factors related to the use of public transportation (CUTR, 1989) Apogee Research's 1990 Trip National Transportation Survey for the Road Information Program consisted of a n ationwide samp l e ol2,351 persons who were also i nterviewed by tel ephone. Respondents were questioned about their satisfaction with infrastructure their perceptions of congestion and potential solutions, and their willingness to pay for improvements, among other opinions (Apogee Research Inc., 1 990). America's Coalition for Transit NOW sponsored nat i onal public opinion surveys in 1990 and 1991. For the 1991 version 1 000 telephone interviews were conducted nationwide to obt ain general attitudes on mass transit i ssues, policy alternatives, and funding options (Market Strateg i es, Inc., 1991). At the regional level, at least 22 metropolitan areas have conducted or are planning to conduct household travel surveys during the 1989-1992 period to coinc i de with the 1990 Census (Purvis 1989) Other areas, such as Denver ( 1 985) San D i ego (1986) Baltimore (1988), Philadelph i a (1988) Phoenix (1988), and Wash i ngton, D.C (1987-88), are on a "ten year off-census' survey cycle and will not be planning updates until the mid-1990s Table 1 on the following page lists various regions that are conducting surveys d u ring the Census time frame; current and previous survey years are shown as are the intended purposes or needs the resulting data will serve. Some surveys were undertaken I n order t o update existing travel and socio-econom i c data bases; most were completed during thi s


15 Table 1 Regional Household Travel Surveys Region Year Prevtoua Need/Purpose Albuquerque 1900 1962 travel demand model development Allanta 1900 1980 travel data. 0-0 data Boston 1900 1963 update work & non-work trlp models Buffalo 1900 1973 travel data Chicago 1988-92 1979 travel data Cleveland 1992 1978 update mode choice models Columbus 1989 1988 socio-economic & travel data Dallas/ft. Worth 1989 1984 travel data Detroit 1900 1980 update travel models, travel data HoustonjGalveston 1900 t984 updale travel models, travel data Kansas City 1900 nta travel data Los Angeles 1900 1976 update travel models Milwaukee 1991 1984-85 updale travel models, travel data Minneapolis/St. Paul 1900 1982 updale travel models, travel data New York 1900 1963-64 travel data, 0-D data Pittsbu rg h 1900 1978-80 travel data Portland 1900 1985,88 socio-economic data StLouis 1900 travel data San Antonio 1900 n/a travel data San Francisco Bay 1900 1981 SOCICHlCOOOI'IIIC & travel data Seattle 1989 1985-88 travel data Tucson 1989 n/a travel data Source: "Survey of Travel Surveys II," Chal1es L Purvis, October t989.


16 time period in order to take advantage of the data from the 1990 Census for comparison purposes. Following are brief descriptions of selected surveys. New York's Metropolitan Transportation Authority (MTA) conducted a comprehensive travel survey in 1990 consisting of a telephone survey, a subway passenger survey, and a survey of Long Island Railroad passen gers (Wheeler and Brown, 1991 ) MTA conducted more than 20,CXXl interviews and collected data from more than 45,CXXl trips to gain informa tion on the travel characteristics in the MTA service territory including New York City, Long Island, and the counties immediately north of the city. The primary goal of the study was to increase knowledge concerning transit use in the region. MT A sought information on transit users, market share, modal competition, and opportunities for growth and ridership maximization. They believed that detailed user data would be useful in future service design, as would knowledge of the areas with transit potential. The results of the surveys revealed lower actual market shares as well as lower than predicted shares In a number of areas. This information, along with the identification of auto zones: could be compared to service delivery characteristics in those areas. Wrth this knowledge, strategies to establish transit or increase market share in those areas could then be formulated. Transportation planners in the Minneapolis-St. Paul seven-county metropoli tan region have recently completed the 1990 Travel Behavior Inventory


17 (TBI), a .ID.a]or travel study that was used to update the region's travel and . . . demographic data base (Alderson, 1991). Facing significant, long-term increases in the demand for highway and transit set"Jices, many planners in the Twin Cities region believed that more current data were required since the primary data base on regional travel was over 20 years old. Under the direction of the Twin Cities Metropolitan Council, Minnesota Department of Transportation, and Regional Transit Board, this study was undertaken to obtain reliable, up-to-date data in order to improve the quality of the planning and delivery of transportation services provided to the public. The study consisted of several components, including a home interview survey, transit on-board surveys, traffic counts and origindestination studies, an employment survey, land use mapping, and an update of specific elements of their travel forecast models. From the resulting data base of information transportation and planning officials will be able to identify travel needs and demand, evaluate current policies and service, and plan and design transportation improvements that will meet current and future needs. San Francisco Bay Area's Metropolitan Transportation Commission (MTC) completed a major telephone travel survey in 1990 (Rodenborn and Purvis, 1991) The survey of nearly 12,000 households In the nine-county region was undertake n to update previous surveys conducted by the Bay Area Transportation Study Commission in 1965 and by MTC in 1981. Detailed


18 household person, and trip data were collected for all household samples. Socio-economic information collected included household size, vehic l e ownership, age and gender of each household member household income, and employment status. Trip data I ncluded start and end t i mes, destination, mode of travel, purpose, and parking cost or transit fare, depend i ng on mode. From this survey MTC was ab l e to estab l ish a current, regional transportation data base. Th i s data base i s expected to aid in the develop ment of regional trave l demand mode ls, provide current estimates of travel characteristics as well as changes that occur over time, and provide a research data base for the analyses of r esidential mobility, job mobility, and travel behavior in the Bay Area. Need for Travel Data It is evident that there are a large number of sources from which to collect transportation related i nformation. However it is not so clear why thi s data i s n eeded and for what purposes it can be used The first step to understanding this need is to examine the reasons behind the establishment of a regional data base A useful transportation data base consists of both demographic characteristics of a particular reg ion's populace (age, gender, race, income, auto ownership, household size, employment status, etc.) and the trave l characteristics of those persons (vehlde trips and miles per time unit, mode of travel, trip purpose, tri p length, auto occupancy etc.).


19 These data can be extremely useful when establishing or updating reg i ona l travel models. Soda-economic variables from the data base can serve dlrecUy as inputs i nto various travel models (trip generation model, work t rip mode -choice model, ate.), or can be used as secondary sources for checking the validity of model inputs such as tri pl ength frequency d i stributions trip ends, and work-trip tab l es (Sosslau, 1984). These variab l es can also be used to recalibrate existing models or to aid in the verification of model results The data base I nformation can also ba used in the application of nonmodel transportation plann in g and analys i s Citize n s travel needs can be identi fied, and l ocal transportation policies and p l ans can ba evaluated and improved as necessary to fit the identified needs. As the data base is updated, changes in cha racteri stic trends over time can be evaluated, which would also allow for the design of additional transportation improvements. Transit planning would benefit since demographic data such as i ncome veh icl e ownersh i p and age can be used to Identify areas with a h igh propensity for t ransi t use. Transit agencies would find these data beneficial when planning route extensions or cutbacks, or changes in the amount of service provided to part icular a reas. The data base also enables the understanding of the geographic d i stribution of travel in the region along with trave l mode selection and the travel duration by mode. This knowledge of travel behavior, the distribution of origins and destinations, and transit service characteristics can lead to the Identification of


20 potential transportation demand management techniques that could be used to alleviate congestion or improve environmental conditions. Urban development would also benefit when various demographic and travel data are used by land-use planners to determine the impacts of proposed traffic generators on the surround Ing roadway network; necessary improvements to the local infrastructure can be planned for and instituted concurrently with the new developments to ensure sufficient supply for the additional traffic. These are but a sampling of the potential uses for extensive socicreconomic and travel behavior data by transportation and urban planners. Decisionmakers would also benefit since they would be able to make properly informed decisions concerning public policy and future planning. Knowledge of their region's travel behavior and needs would enable them to identify spending priorities when programming transportation funding. Forecasters' projections would become more reliable since they would now be based on up-to-date information. However, it must be stressed that these benefits are contingent upon the accuracy and currency of the data Regional transportation plans, models, and forecasts all rely on the accuracy of the data on which they are based. Data from the late 1970s and early 1980s would not need to be updated if trends were relatively nat and socio-economic and travel data remained status quo; the plans, models, and forecasts would maintain their validity. However, it i s evident from a review of numerous sources that demo-


21 graphics and travel characteristics have indeed changed in the last few decades (FHWA, July 1986; Pisarski, 1987; -USDOT, July 1988; Preveclouros & Scholer, 1989; Hartgen, 1990; Lave, 1990). Therefore, these plans and models require updating due to the obsolescence of their base data. This then, is the reason why planners and MPOs have eagerty awaited the results of the NPTS and the Census Journey-to Work data This Is why many regional and metropolitan plann i ng agencies have conducted or are planning to conduct supplemental travel surveys. With current national data now being available for demographic and travel behavior characteristics, outdated data bases can be revised accurately with modest investment in time and cost, and the results of smaller-scale travel surveys have a basis for comparison and assessment. This need for current, accurate data highlights the Importance of these recent surveys as well as emphasizes the value of the analyses of their r esult i ng data. current Trends In order to better analyze and interpret survey data, it is important to establish a framework of re;il-world information and trends from other data sources. This framework, then, can be used to compare and assess the new survey data, and it may even provide Insight into some of the reasons for the results. In Chapter 5 this methodology is utilized to compare and contrast "peer survey data ; however, a more general understanding of current nationa l and Florida trends is first needed. Following are brief overviews of demographic and trave l


22 related data that have been collected for both Florida and the nation from several publications such as Commuting In America, Highway Statistics 1989, Statistical Abstractotthe United States: 1991, MYMA Motor Vehicle Facts & Figures 91, 1989 Highway Fact Book, ITE Mobility Facts, and the Florida Statistical Abstract (1991 edition and previous. National Trends In the last four decades, population i n the United States has i ncreased over 63 percent Evident in Figure 1 is the changing areal distribution of the populace that has occurred during this time period. In 1950, the majority of U .S. residents lived in areas of the nation (44 percent) while only 23 percent inhabited the suburbs. By 1989, increasing suburbanization of the population resulted in a 48 percent population share for the suburbs and only a 21 percent share for non-metropolitan regions Ce n tral city population has remained stable throughout, w ith just over a 30 percent share. As would be expected, this increase in people has produced similar increases in related demographic characteristics. Figure 2 d i splays the trends o f several of these assoc i ated variables, all of which have shown greater percent increases than that of population since 1960. The growth in households has led to a decrease in household size, from 3 33 (1960) to 2.63 persons per household In 1990. Similarly, vehicle growth at a rate greater than household growth has produced increases in the number of vehicles per household (1.04 in 1960; 1.80 in 1988). Most interesting to note in this figure is that vehicle registrations surpassed licensed drivers sometime in the early 1970s.


B Subllrt>s [] Central c;,y """""'01r0 200+---+-100 50 0 1950 1960 1970 1980 1984 1989 Figure 1 D i stribution of the U S. popu lation (millions). 300 250 200 150 100 . ... Population ....... ...... -1RegdVaha Uod Drivers 0 0 .... . . . . . . .. . . . . .... 0 0 -.. ....... .......... .......... 1........ ................. .......... .. .. .................. .. ........................ .................... ......................... ... ... ..... 0 1960 1 970 1980 1990 Figure 2. National trends of demographic characte ristics (millions). 23


24 It can be argued that several of these factors contribute directly to traffic congestion, currently a major transportation issue. According to Apogee Research's 1990Trip National Transportation Survey, 75 percent of all respondents believed congestion to be a problem In their area, and 48 percent believed the problem to be major. Defining congestion as the mismatch between traffic and road space available" (Hartgen, 1990), Figure 3 examines this relationship between road supply and travel demand. Assuming that these increases in population, drivers, vehicles, and VMT have translated into additional demand on our highways then the corresponding increase shown for roadway mileage will not help alleviate the problem of congestion, especially with other trends compounding the travel demand dilemma, such as increased female labor participation and the aging of the population. Figure 4 illu stra tes the labor force distribution since 1950 In that year, wome n comprised only 28 percent of the total civilian labor force in the U.S. Their share has increased to 45 percent in 1990. The age distribution of the population Is shown in Figure 5. The 16-64 age category has increased from a 58 percent share in 1960 to a 65 percent share in 1989. The number of people age 65 and older also has increased during this period, from 9 percent to 12 percent of the total population This aging of the population I s further evidence supporting the increases in drivers and workers, and it means that more people will be at an age that affords them higher activity participation and mobility. These data demonstrate that there are many factors that can affect the amount of demand placed on the nation's transportation infrastructure. I n Figure 3, it was


Road Mileage Population Ucsd Drivers Vehicle Regstms Vehicle Miles 0% 50% 100% 150% 200% 250% Agure 3. Changing road supply and travel demand in the U.S., percent change 1960-89. 60 30 0 1950 1960 1970 1980 1990 Figure 4. Distribution of the U.S. civilian labor force (millions). 300 6Syro+ <18yro r',.l18-84 yro 200 160 100 60 0 1960 1970 1980 1990 Agure 5. D i stribution of the U S population by age (mi llions) 25


26 shown that VMT has increased over 190 percent since 1960 The trend for this measure is presented in Figure 6. In the figure, VMT is represented by three trend lines. The solid line represents total VMT for all passenger vehicles (cars, motorcycles buses) and truck types (2-axle/4-tire, other single units, trailer combinations). The dashed line Includes only cars, buses and motorcycles and the dotted l ine represents all trucks. In addition to increasing VMT, the number of registered vehicles was also shown to have I ncreased. This trend has spurred an increase in the average number of vehicles available for use by each household. F i gure 7 high li ghts the trend of vehicle availability. Th i s graphic clearly shows the decline in zeroand one-auto households, while households with two or more vehicles are on the r i se. In 1988 over one third of the households in the nation had two vehicles available for use, despite the decrease In average househo l d size and the stability in the average number of workers per household. I t is no surprise, then that private vehicles have become the mode of choice for making the journey to work. Modal shares for the work commute are shown in Figure 8 From 1960 to 1990, only the private vehicle has increased its modal share. During th i s period, public transit s share has been steadily declining, a fact exacerbated by a concurrent decrease in intercity bus passengers of 12 percent. Despite thi s disappointing current utilization of pub lic transit, it is still a va l uable resource in dealing with increased travel demand and demand by those with no auto option. Florida Trends In 1990, the Ce n sus results placed Florida as the fourth most populated state in the nation. Florida hac; also been one of the fastest-grow i ng.


2,500 2,000 1,500 1 000 500 Total ....... Pua. Veho. ...... TNCice v-::. ... ....... ................... .............. / ...... .. 0 1 960 1970 1 980 1990 Figure 6 Vehicle miles of travel {VMl) In the U.S. (billions). Figure 7. Percent distribution of the number of household vehicles available in the U.S. 100%.-----------------, 1---1 J--+ + PublicTtanlit Walk to Wc

28 Since 1950, Ronda's population has increased nearly 370 percent; it grew approximately 33 percent in the last ten years, the majority of this growth resulting from net migration (28 percent). Florida's population is considerably more metropolitan in distribution than that of the United States, as is reflected in Figure 9. Just as. for the U.S., the increase in Florida's population has created corre sponding increases in related demographic characteristics. Figure 10 presents the trends for vehicles, drivers, workers, and households. Similar to the national trend, Ronda's average household size is decreasing. In 1990, there were only 2.46 persons per household, on average, compared to 2.63 persons at the national level. This is down from an average of 3.10 persons per household in 1960. Despite the smaller average size, the number of households has grown along with several other factors that contribute to increased travel demand. Significant increases in licensed drivers, registered vehicles, and VMT have occurred since 1970, increases that, similar to the U.S., have not been met with corresponding increases in road supply, as shown in Figure 11. As mentioned previously, this supply/demand mismatch often results in traffic congestion. The potential for congestion Is magnified when Florida's increasing labor force and aging population are taken into consideration. Figure 12 illustrates Aorida's increasing labor force and employees. The civilian labor force increased 240 percent since 1960 while employees rose over 236 percent, signifying an increase in the rate o1 unemploy ment. In 1990, the labor force distribution between males and females was 54 percent and 46 percent, respectively, a percent split similar to that of the nation.


Non-MetmpoliiM Melropoli!an Florida U.S. Fogure 9. Pe""'nt distributicln of Florida and U.S. population between metropolitan and noiHilelrOpoitan areaa, 1990. Road Mileage Population lJc&d Drivers Vehicle Regstms Vehicle Mllee O'J6 50% 100% 150% 200% Figure 11. Changing road supply and travel demand In Florida, p8IC8III change 1970-89. ..... -Lied o.t.otr. ---.. ttct..hOiclt -----15 ... :/ . . . . 12 ...... ''/ v ... 9 e .. .. .. ./ 3 ................ ..... 0 1980 1970 . .-1980 1990 29 Figure 10. Florida trends of demographic chatac:terlsties (milions). 4 2 0 1960 1970 1980 1990 Fogure 12. Trend in Rorlda's cMIIan labor ton:e and employees (miUions).


30 The distribution of Aorida's aging population is presented in Figure 13. Since 1960, the 15-64 age category has increased from a 59 percent share in 1960 to a 63 percent share in 1990. The 65 and older age category has also increased during this time, from 11 to 18 percent of the total population. This share for those persons 65 or older is considerably higher than the 12 percent share nationwide, a statistic that supports Florida's popularity as a retirement haven. Figure 14 displays the availability of vehicles to Aorlda households for 1990. It is clear from the graphic that the majority (approximately 78 percent) of Florida households have one or two vehicles available for use. For comparison, figures for vehicle availability in the U S. in 1988 are also shown. While Florida has a lower percent share of zero-vehicle households, it has a significantly higher percent share of one-vehicle households. The nation's higher percentage of three or more vehicle households is one reason fo r its higher average number of vehicles per household (1.8 versus approximately 1.6 for Florida). Florida's smaller average household size has also contributed to its comparatively smaller average number of vehicles per household. Similar to the U .S., the high availability of vehicles to Florida households has translated into the overwhelming use of private vehicles to make the work commute. Aorida's 1990 modal shares for the journey to work are shown In Figure 15. The figure shows that Florida workers utilize private vehicles more and public transit less than workers across the nation. Over 93 percent of all work trips


f!SY!". + 12 lill15-64yrs f----+----: 9 0 1960 1970 1980 1990 Figure 13 Distribution of Florida population by age (millions). 40%+---30%+---Flol1da. 1990 u.s . 1988 Figure 14. Percent distribution of the number of household vehicles available in Aorida and the U.S. Florida United s-Frgure 15. Florida and U.S. Journey to work modal shares, 1990. 31


32 I n Aorida rely on some sort of private vehicle while only 2 peroent make use of pu blic transit Also Florida worl

33 AN OVERVIEW: NPTS AND SAS In the Introduction, Chapter 1 a brief review of the Nationwide Personal Transpor' tation Study ( NPTS) was presented In addition, the methodology for the analysis used In this project was reviewed with regard to the software and procedures used to manipulate and analyze the data. This chapter presents a more detailed overview of the NPTS surveys, particularly the 1990 version. The SAS software Is discus:;ed as are the various procedures that were used to analyze the data. 1990 NPTS Survey The 1990 NPTS survey was conducted under the sponsorship of five U .S Department of Transportation (USDOT) agencies: the Federal Highway Administra tion (FHWA), the Fede ral Transit Administration (FTA, formerly UMTA Urban Mass Transportation Administration), the National Highway Traffic Safety Administration (NH T SA), the Office of the Secretary of Transportation (OST), and the Federal Railroad Administration (FAA). The survey was designed to address program and policy issues iri each of the five agencies. FHWA the technical and administrative lead for the survey, described the NPTS as a national survey of trips and travel that would provide the data needed at the Federal level to assess the relative use of var ious modes of travel and to provide I nformation on the characteristics of commuters and their trips (FHWA, Augt

34 the NPTS represents the QD& national data collected by USDOT that includes trip purposes and allows driver, vehicle, and trip characteristics to be compared. The NPTS survey has been conducted at approximately seven-year intervals since the late 1960s Previously administered in 1969, 19n, and 1983, the 1990 version of the NPTS is the fourth survey of the series. This ins t allment was conducted by the Research Triangle lnstiMe (RTI), a private, non-profit organization in the Raleigh-Durham area of North Carolina that has experience in conducting large scale social science surveys for the Federal Government. Survey data collection began on March 2, 1990, and continued until March 24, 1991. The data were collected over a full calendar year to ensure the representa tion of seasonal variations in travel. Characteristics of all trips were collected, by all modes (except boat or ship), for all eligible household members (age 5 and older). Trip data were collected for both "travel days and "travel periods." The travel day was defined as a 24-hour period, usually the previous day, for which all of the respondent's trips were reported. The travel period, a two-week period designated for the reporting of long trips (75 miles or more, one way), was used to improve overall travel estimates since any given travel day would not necessarily be representative of intercity trips or other extended travel. RTI's Telephone Survey Unit conducted the survey using a computer-assisted telephone interviewing (CA TI) system (A copy of the survey questionnaire used


35 by Rn can be found in Appendix A.) The CAn system enabled real-time, on-line editing so that data inconsistencies and quality problems could be identified and corrected during the course of en interview. This techno logy also provided computer-controlled branching for the questionnaire so that the computer would automatically skip questions that did not pertain to a respondent based on the person's previous responses. The resulting CAn data base was subdivided into six separate data sets: household file (22,317 records, 71 variables), person file (48,385 records, 102 variables), vehicle file (41,178 records, 48 variables), travel day file (149,546 records, 102 variables), travel period file (12,852 records, 102 variables), and segmented trip fi le {1,165 records, 40 variables). EXtensive post-processing edits were completed on these files to reformat the data; to check for accuracy, consistency, and completeness of the data; and to assign logical variable names. RTI's sample consisted of 26,172 households that were identified using a random digit dialing (ROD) procedure. This sampling procedure was used so that unlisted telepho ne numbers were included in the sample frame. The sampling frame was stratified by size of area, region of t"le country, and presence/absence of a subway or rail system (for metropolitan areas of 1 million or more In population) so that the sample would better re present the nation (FHWA. August 1991). From


36 this sample, 21 ,869 unique household inteN iews were completed, a r esponse rate of 84 percent for all eligible households contacted. The response rate for the collection of trip and travel info rmation from eligible persons with in the surveyed households was 87 percent (47,499 of 54,313 person-level interviews). Since the sampling design that was used allowed a phone number to be selected multiple times, interviews could be and were, in fact, duplicated. Because of this duplica tion, the final data base contained 22,317 household interviews (21,869 unique + 448 duplicate) and 48,385 person interviews (47,499 unique + 886 duplicate). The household and person interviews produced raw data for 1 49,456 travel day trips (one-way). RTI developed a series of weights for the raw data that reflect ed the sampling procedure and selection probabilities, as well as the necessary adjustments to compensate for survey nonresponse and noncoverage (FHWA, November 1991). The weights were then included in their respective data files so they could be used to expand the sample data to national estimates. Among the travel data collected were vehicle and person trips, vehicle-miles and person-miles of travel, trip duration and distance, trip purpose, vehicle occupancy, and mode of transportation. Various household demographic data were also collected: household income, size of household, number of vehicles owned by household, and employment information for working-age members. Assorted other data collected were information on the availability of public transportation, motor vehicle information, and traffic accident data and reporting.


37 Com!)ilrabfllty of the 1990 NPTS As discussed in the preceding section, RTI conducted the entire 1990 NPTS survey, from sample design to the calculation of the final data set weights. This marks the first time that the survey was not conducted by the Bureau of the Census, as it had been in 1969, 1977, and 1983. However, this Is not the only procedural change from the previous surveys. The 1990 NPTS differs in several other aspects (FHWA, August 1991; FHWA, November 1991; FHWA, March 1992). Table 2 outlines the differences among the surveys. Contractor Sponsor(s) Surwy Method Data Ed111ng Sampling Use of Proxy Sample Size Table 2 Comparison of NPTS Surveys 1969 19n 1983 Census Bureau Census Bureau Census Bureau FHWA FHWA, NHTSA, FHWA, NHTSA. OST. FTA OST. FTA Home Interview Home Interview Home Interview End of Month End of Month End of Month Address Address Address Not Allowed Not Allowed Not Allowed 15,000 18,000 6,500 1990 RTI FHWA. NHTSA. OST, FT A. FRA CATI Real-Time ROD Allowed 22,317 The first noticeable difference, aside from the change in contractors, is in the methodology used to conduct the surveys. The 1990 survey was conducted as a telephone survey while the Bureau of the Census conducted the previous


38 surveys as personal home interviews. The method used in 1990 excluded those households that did not have telephones from the sample. As a result, the weights that RTI developed had to take this methodology into account so that expanded estimates from the data would represent all national households, not just those with phones. The second evident change is in the editing of the survey data. Using the CATI system, the 1990 data could be edited while on-line during the course of the interview. Previously, the survey data were at the end of each month of data cpllection. This made it extremely difficult to solve data inconsistency or quality problems days, or even weeks, after it had been collected. A third difference is in the methodology used to sample households. The 1990 NPTS used the random digit dialing (ROD) sample. The earlier surveys utilized address samples that were based on area-probability household sampling techniques. Another change in procedure involved the use of proxies to report another household member's trips. Originally, this practice was not allowed. However, in the 1990 survey, it was permitted that any knowledgeable household member could provide proxy Information for any other household member that could not be reached for an interview after repeated attempts.


39 The final difference among the surveys is the sample size of each survey In 1961, there were 15,000 completed interviews In 19n and 1983, there were 18, 000 and 6,500, respectively The 1990 NPTS included 22,317 completed surveys. Obviously, it is better to have a larger number of surveys from wh i ch to draw information ; however, the impact of these varying sample sizes on comparability among the surveys cannot be easily quantified Another potential concern is the effect that the more than 3,800 MPO tunded interviews (State of Connecticut, New York MPO, and Indianapolis MPO) have had on the 1990 survey data In order to eliminate this overrepresentation of the north eastern region of the U.S RTI weighted down this data rel ative to the data from the other areas of the nat i on. Therefore these additional I nterviews should have had no effect on the nat i onal trave l behavior characteristics or demographics that resulted from the analysis of this data base Statistical Ana lysis System (SAS) The analysis of the 1 990 NPTS data was completed us i ng the SAS System, version 5.18 accessed via the Central F l o rida Regi onal Data Center (CFRDC) at the University of South Florida. The software runs under the VM /XA host operating system that is utilized on the Un iv ersity's ma i nframe IBM 3090-300E SAS job files were created and run from WYLBER, an on-line edit/submit system provided by . CFRDC The three primary SAS procedures, commonly referred to as procs," used in the analysis of the data were Proc Freq(uency), Tabulate, and Means.


40 The Proc Freq procedure was used to produce response frequencies for basic demographic and travel data. This procedure was also used to calculate cross tabulation tables for related variables such as number of vehicles by household Income, vehicle trips by mode of transportation and trip purpose, and average annual miles driven per driver by age and gender. Both unweighted and weighted response frequencies for the nation and Florida were obtained, as well as percentages of the category totals. The Proc Tabulate function was similar to Proc Freq in that it could be used to produce simple frequencies and to cross-tab related variables; however, it differed in its ability to produce more extensive classification tables. This procedure enabled a greater degree of flexibility in the hierarchical stratification of the data. For example, the Tabulate procedure was used to cross-classify males and females by age and by whether or not each respondent was employed and/or a licensed driver. Again, weighted and unweighted results were obtained for both national and Florida-specific data. The Proc Means function was used to obtain descriptive statistics for various data. Statistics that could be calculated with this procedure inc lude the mean of a variable, the standard deviation, standard error of the mean, variance, minimum and maximum values of a variable, and others. Primarily, this procedure was used to produce household averages for certain variables such as persons, workers, and drivers; vehicle trips and miles; and person trips and miles.


41 As discussed in the introduction, the analysis of the resulting frequencies and . cross tabu l ations was conducted us i ng three separate analyses: Florida versus the nation, a trend analysis, and a peer survey review. The first analysis Involved the comparison of selected demographics and travel characteristics for Florida to national results for the same characteristics. Demographic characteristics that were examined Included age, gender, race, hispanic origin, household Income, household size, vehicle ownership, licensed drivers, workers, and size of urban area. Travel behavior character i stics included mode choice, trip purpose, person trips and m i les, vehicle trips and miles, trip distance, travel time, availability of and d i stance to public transit, and vehicle occupancy. It should be noted that some of the variables were analyzed only in the context of other related variables. Also, due to the disparity in surveyed households (22,317 nationally, 930 in Flor i da), averages and percentages of weighted data were used to make the comparisons. The second analysis compared selected 1990 NPTS demographics and travel characteristics to results from the 1969, 19n, and 1983 surveys in order to establish any significant changes over time (trend analysis). The information used in this analysis for the earlier NPTS surveys came from published reports about these studies since it was not possible to analyze the actual data tapes for the previous three surveys Finally, the third analysis involved the comparison of selected 1990 NPTS data with data from various peer surveys or other data sources such as the 1989 American Housing Survey the 1988 Residential Transportation Energy Consumpt i on Survey and.Highway Statistics 1989, among


42 others. This analysis was completed to get a better overall understanding of the transportation and demographic characteristics of the United States. II stands to reason that national estimates of travel improve when there are more data available for comparison and analysis purposes.


43 RESULTS: FLORIDA VERSUS THE NATION This chapter presents the results of the analyses comparing demographic characteristics and travel behavior for Florida and the United States. As mentioned previously, averages and percentages of the weighted data were used in the analyses to compensate for disproportionate samples. There were 22,317 households surveyed at the national level, producing 48,385 individual responses. The 930 Aorida households that were surveyed generated 1,691 response records. It should be noted that for several of the response variables, answers of "don't know or "refuse to respond" were permitted and are Incl uded in the estimated totals for such variables as number of persons, workers, and licensed drivers; modes of travel; trip purpose; and household income. Percentage breakdowns within these categories were based on the totals excluding the undetermined responses Also, all data tabulations based on number of persons included only those persons age 5 years and older since these were the only household members from which pertinent info rmation was obtained. F HWA's User's Guide for the Public Use Tapes estimated a weighted total of 17,315,000 persons under age 5 using a variable from the household file Demographics On the following page, Table 3 highlights selected characteristics for Florida and


44 Table 3 NPTS Comparative De m ographi c and Tra v e l Characteristics UnHed S1ate FlOrida >..'<,,,,, 1: r "'C:.zlli 1 2 5% 27% 2 32% 39% 3 1 7% 16% 4+ 26'1(, 5-15 17% 15% 1 619 6% 6'1(, 20-29 17% 17 % 30-3 9 19% 16% 405 9 2 4 % 22% 5 % 7% 85+ 12% 17% 5-15 9'1(, 8% 16+ 39% 39 % 5-15 9'1(, 7% F emale, 18+ 43% 46'1(, LieenMd DriVer. (OOo), .: I;., :;,_ .,; 7 '/ Male 4 9'1(, 48% Female 51% 52% 1': .. ., <;.. ,., ,.Q ..... ,; '::.:: 4, 575 .,:, Mal e 54 % 53% Female 46'1(, 47% ' !". H ouHhokl Vehicle 'nnn nnA '7 "" HouHhold VMT 'nnn nnA' ... 53,604 Perton '""" '""" """' AAA rrA "1,617 Perton Mllet of Travel 'AAA AAA' 2,315.273 Soutce: Household. person and travel day Illes; s u mmary ol Travel Trands : 1 990 Nationwide Personal Transpor1atlon Surve y,' FHWA, M arch 1992.


45 the nation. These data reflect weighted totals for the variables compiled from the h ouseho ld, person, and travel day files of the 1990 NPTS use r tape. Florida totals for each of the main variables (persons, households, drivers, workers, vehicles, and travel data) accounted for approximately 4 to 5 percent of national totals. According to the distribution of persons per household, Florida's households i : tended to be smaller In size than those nationally. Aorida had a slightly higher share of one-person households and only 34 percent of all households consisted of three or more persons. This compared to 43 percent of national households with more than two. persons. Table 4 shows selected average household characteristics for both Aorida and the U.S. Table 4 Average Household Characteristics United States Florlcla Persons (5+ years) per Household 2.38 1.99 Ucensed Drivers per Household 1.75 1.51 Worl

46 persons. The sma ll er household size also affected Florida's other household character istics as well Less persons translated into fewer licensed drivers and worlut the percent share of household members who worl

1 person 2 persona 3 persons 4+ persons Total Table 5 United States Average Annual Household Travel By Household Size and Vehicles Available Oveha 1 veh 2 veha 3veha 4+ veha 28 trips 1,097 1,292 1,464 1,263 196 mRes 8,192 12,732 21,322 16,757 74 1,154 1,811 1,972 2,076 383 7,993 16,903 20,534 26,190 109 1,445 2,195 2,654 2,679 665 10,759 20,016 28,000 28,032 189 1,543 2,411 2,833 3,452 768 10,887 20,074 25,322 34,099 63 1,206 2,039 2,501 2,971 343 8 723 18,232 24,702 30,855 Source: Travel day file. 1 person 2 persona 3 persons 4+ persona Total Table 6 Florida Average Annual Household Travel By Household Size and Vehicles Available 0 vehs 1 veh 2vehs 3Vehl 4+ vehs 35trips 969 831 1,957 n/a 41 miles 5,561 3,116 6,936 n/a n/a 1,008 1,723 2,438 1.864 nja 6,337 13,812 28,489 11,143 345 1,644 2,231 2,301 3,415 2,816 9.236 14,400 18,263 27,238 1,303 1,954 2,382 2,052 2,409 5,576 13,623 20,065 17,493 25,791 132 1,141 1,913 2,249 2,634 603 6,947 14,725 20,367 24,473 Source: Travel day !lie. 47 Total 887 7,164 1,560 14,247 2,065 19,434 2,417 20,839 1,703 15,100 Total 777 4,180 1,480 11,958 2,097 14,324 2,213 18,548 1,521 11,418


48 Another characteristic analyzed at the household level was income. It was determined from the data that, while not being d r astically different, Aorida had a higher percentage of lower income households than did the nation. Fifty-seven percent of Aorida households had Incomes of less than $30,000, while the U S had 51 percent below that income level. This finding can be attributed to the smaller average number of workers per household in Aorida; analyses of these variables showed that they were directly proportional. Also, it was determined that average vehicle availability increased with escalating household income for both Aorida and the nation. Table 7 presents the percent income distribution for Florida and the U.S. households and the associated average number of household vehicles for each income category Table 7 Household Income Characteristics UnHed States Florida '!+ :. % ol HHa'> Avg II VeilS JA\;j\ II Viha, Leaa than $5,000 4% .81 3% 1.05 10% 1.01 12'11. 1 01 $1H14,ett 9% 1 .25 11% 1.22 10% 1.48 10% 1.33 $20-$24,8tt 8% 1.61 9% 1.54 $25-$29,8tt 10% 1.75 12% 1.57 $3H38,8tt 17% 1 .95 16% 1.73 $40-$4t,eee 10% 2.12 9% 1.97 9% 2 .32 7% 2 .22 $80,000 or more 13% 2 .53 11% 2.14 Source: Household ard travel day ties.


49 Other fandings at the household level included the metropolitan/non-metropolitan . distribution of the population for both Florida and the U.S. and the availability of and distance to public transportation. Nationally, 37 percent of the population maintained their households within the central city of a metropolitan region; 40 percent lived within the metropolitan area outsid e of the central city, i.e., the suburbs. The remainder of the populatlon resided in non-metropolitan regions. The distribution for Aorlda was 46 percent In the metropolitan central cities, 43 percent In the suburbs, and 11 percent In non-metropolitan regions. These values were found to be consistent with the distributions discussed in Chapter 2. The avaJlability of public transportation was comparatively s imilar tor the U.S. and Aorida Fifty-eight percent of national households had access to transit, while 56 percent of Florida households had access. Of those national households with access, 61 percent were within 3 blocks of public transportation and 88 percent were within 12 blocks. Florida households were similarly distanced from transit, with 55 percent w i thin 3 blocks and 89 percent w i thin 12 blocks. Analyses were also completed on data at the person level for various demographic characteristics. As was shown in Table 3, the age distr i bution for Aorida and the U.S. were relatively similar, as was the gender distribution. Flor:_ida did have an older population however, as evidenced by the 24 percent of persons that were 60 and older; only 17 percent of the nation was in this age category. Aorida also had fewer persons (38 percent) in the 30 year category than did the u.s. (43 percent). The breakdown of males and females was 47 percent end 53 percent


50 in Florida and 48 percent and 52 percent for the nation. For both Florida and the U.S., more women were licensed drivers and more men were workers. Demographic information on race and. H ispanic origin are presented in Table 8. Table a Race and Hispanic Origin United States Floricbl White 80% 82% Afrtcan-Amerlcan II% 13 % Other 8% 4% .:'' .. . :: ( >-' .... ... -.., : ;f ; ' '::'$;)-:-':,. ,v;; "'*' 0 0 ' .. Hlap1nlc 8% 9% Not 92% 90% Source: Person file. The data showed both the U.S and Florida to be predominantly white, with only a small percentage of persons of Hispanic origin. Florida did have a higher percentage of African Americans than the nation, as well as a slightly higher proportion of Hispan i c persons. Analyses of the vehicle-file variable--owner estimated annual miles-produced interest ing results by race. For Florida, African Americans averaged the most annual miles of any race, at 21,356 miles. The overall average for Florida was only 13,036 miles, and whites averaged 12 ,392. Nat ionally, the overall average was 12,458 miles and persons in the "other" race category had the highest annual estimated mileage-13,584 mites. African Americans averaged 13,340 miles and whites averaged 12,339.


51 Table 9 exam i nes the distnbution of licensed drivers by age and gender for Florida and the U.S For both, the total of licensed drivers 16 years or older are distributed by age category and gender. The "% of eligible" column Illustrates the percent capture of the population In each age bracket thet were licensed drivers. For example of all the persons In the U.S. that were between the ages of 16 and 18 years, 64 percent of them were li censed drivers. The Inve rse of this is that there were some 3.7 m i llion teenagers i n th i s age group that were eligible to drive but did not yet have a license. These percentages are useful in examining the potential additional drivers in each age category. In total, 88 percent of the nation's population and 89 percent of F lorida's population were lic ensed d ri vers. Table 9 Dist ribution o f Ucensed Drive r s By Age and Gender United State Florida 'iA!le"citisi ] :female . '", .;;, ..;... ........ % o t Eligible .:::. ... _female ... ---*--. "<" ... _,., . ... ,_,. 4 ... ... ....... 1&-18 2% 2$ 64% 2$ 3% 75% 4% 4% 88% 3% 4% 90% 23-34 14% 14% 93% 13% 15% 96% 3&-46 12% 12$ 95% 8% 8% 94% 4&-St 8% 9% 92% .In(, 8% 92% 6064 3% 3% 88% 4% 4% 88% .74 4% 4% 83% 5% 8% 83% 75+ 2% 2% 83% 4% 3% 70% Tolal 48% 51% 88% 48% 52$ 88% Source: Person file.


52 Travel Characteristics In addition to socio-economic data, travel characteristics such as vehicle trips and miles, person trips and miles, mode choice, and trip purpose were also analyzed in the context of various cross-tab variables. Table 10, for example, presents ave rage daily vehicle trips and vehicle miles, as well as the associated trip lengths, for both the U.S. and Florida by age and gender. This and all other travel data resulted from the analyses of the NPTS day trip file. Further analysis of the data showed that men In the United States made a higher number of average daily vehiCle trips (2.09) than women (1.84) Both the men and women i n the 30-39 age category contributed the most to the average number of vehicle trips The situation was similar in Florida, where men made 2.31 vehicle trips per day, compared to 1.91 trips made by women F lorida's overall number of average daily vehicle trips (2.09) was foun d to be h igher than that of the U.S (1. 96). Average daily vehicle miles for both Florida and the U.S. were consistent with the vehicle trip data. Men made more daily vehicle trips and, therefore, traveled more miles each day (21. 93 miles for men and 13.24 miles for women i n the U.S.; 20.04 for men and 11.99 for women in Florida). The only difference found in average daily vehicle miles was tha1, despite a slightly higher average number of trips, Florida's total average daily vehicle miles fell below that of the U.S. (15.73 versus 17 39 miles). An analysis of average vehicle trip lengths showed that this decrease resulted from Florida travelers having shorter trip lengths, 7.51 m iles per vehicle trip compared to 8 .8 7 miles nationally. It was also evident from the data that men made longer vehicle trips than women for both Florida and the U.S.


. T able 1 0 Average Dail y V e hicle Trips, Vehi cle M ile s, and Tri p Len g th B y Age a n d G ende r UnHecl States Florida 53 f. w -. < 1 6 01 trips' .07 mi l es' 4.81 miles' 1 &-19 1.85 15.56 8.40 2o-29 < 2.76 29 n 10 .80 3o-39 2.88 31.92 11.07 4o-49 2.76 31.77 11.50 5o-59 2.51 27.00 10.74 60-64 2 .49 22.44 9.00 65+ 1.84 1 4.05 7.63 TOial 2.09 21.93 1 0 .48 'Awfage vehicle trfpa per day. 2Aomago vtllldt milts pe< day. 3AYotogo vtllldo trip long1h. .02 .13 8.36 1.58 10.99 6.97 2.43 20.26 8 .33 2.95 21.37 7 .23 2.74 18 .99 6 .94 1 .89 13.82 7 .31 1.59 9 .70 6.09 .97 4 .74 4 .87 1 .84 13.24 7.19 Source: Person and travel day files. .01 10 6.60 1.71 13 .21 7.72 2 .59 24.85 9.60 2 .92 26.45 9.06 2 .75 25.23 9.18 2 .19 20.16 9 .20 2 01 15.55 7.75 1.34 8.65 6.47 1.96 17.39 8.8'7 01 .01 .01 .0 4 .07 .06 3 .00 5.00 3 .98 3.13 1.23 2.11 18.08 5 .78 11.50 5.n 4 7 1 5 .44 3 .11 2.n 2.91 23.70 22.n 23.1 4 7.61 8.21 7 .96 3.57 3.08 3.32 32.66 18 .84 25.73 9 .16 6.12 7 .75 2.51 3.19 2.85 33.00 17.60 25.50 13.12 5 .51 8 .96 2.41 2 14 2 .27 22.44 13.07 17.36 9.31 6.09 7.66 2.55 1 .50 2.04 26.83 6.02 16.73 10.54 4 .03 8.22 1.88 1.00 1 .38 11.06 4 .72 7 .49 5.87 4.73 5.41 2.31 1.91 2 .09 20.04 11.99 15.73 &68 6.27 7.51


54 A comparison of average daily person trips and person miles for the U.S. and Florida is shown in Table 11. The table is identical to Table 10 in format except that person trips, miles, and trip lengths are shown. The difference in these data is that vehicle trips and miles are independent of the number of occupants in the vehicle making the trip;. person miles and trips, however, depend on vehicle occupancy rates. A vehicle driving one mile while carrying 10 passengers may only make one vehicle trip, but has actually produced ten perscn trips. Since analysis of this data base required that vehicle trips consisted only of trips in which the respondent was the driver (to avoid the double-counting of vehicle trips), this measure of travel became especially important when analyzing trips made by airplane, public transportation, or other modes on which the respondent was not likely to be driving. From the data shown in Table 11, it is evident that women tended to average more perscn trips per day than men. This was the case for both Florida, where women averaged 3.13 trips per day compared to 3.10 for the men, and the nation (3.12 for women, 3.03 for men). However, similar to the case for vehicle miles, men still averaged more person miles per trip. This is supported by the longer average perscn trip lengths shown for men in Florida (29. 72 miles versus 22.15 miles for the women) and for men across the nation (31.56 miles versus 25.83 for the women). These trip length figures alsc highlight that person trips tended to be longer for persons nationally than in Florida.


55 Table 11 Average Daily Person Trips, Person Miles, and Trip Length By Age and Gender Unhed States Florida <16 16-19 20-29 30-39 So-59 65+ Total 2 .55 trips 16 .34 mues 6.41 maes 3.46 29.77 8.55 3.54 39.69 11.21 3 .37 39.53 11.73 3.15 4o.43 12.84 2.91 35.05 12.05 2.87 26.65 9.36 2.24 18. 14 8.1 0 3.03 31.56 10.40 'Mr penon trips per day. 2AYerage peraon milet per day. AYe,. person lrip lenglh. 2.62 16.07 6.13 3.45 24.82 7.20 3.62 31.95 8.83 3.93 33.50 8.52 3.64 34.65 9.52 2.86 26.78 9.31 2.52 18.59 7.37 1.75 13.30 7 60 3 .12 25.83 8 .28 Source: Person and travel day files. 2.59 16.21 6.27 3.46 27.22 7.86 3 .58 35.68 9.97 3.66 36.41 9.94 3.40 37.47 11.02 2.89 30.76 10.64 2.68 22.39 8,34 1.96 15.33 7.84 3.08 28.56 9.28 2.24 13 .44 6.00 4 .63 31.56 6.82 3.67 28.93 7.86 3.97 45.87 11.56 2.93 42.31 14.46 2.79 26.02 9.34 3.00 30.41 10.13 2 .34 23.65 10.20 3.10 29.72 9.58 2.30 9.95 4.32 3.33 27.41 8,23 3.70 32.25 8 .71 4 .42 29.75 6.73 3.73 2298 6.16 3.16 20.65 6.55 2 .86 13.13 4.58 1.84 17.56 9.57 3.13 22.15 7.07 2.27 11.72 5.16 3.93 29.34 7.46 3.69 3o.93 8.38 4.19 37.79 9.01 3 .32 32.89 9.91 2 .89 23.11 7.74 2.94 22.03 7.50 2.06 20. 31 9.86 3.11 25.66 8.24


56 Vehicle trips and miles, as well as person trips and miles, were also analyzed in the context of other demographic characteristics, such as income and the location of households within the metropolitan area. Table 12 illustrates the distribution of vehicle trips and vehicle miles by household income for Aorida and the United States. Table 12 Total Travel By Income Category UnHed StatH Aorida _,. ' .. lncome Category Yeh Trpl" Veli Mia % ofHHa Yeh Trps HHa Leu than $5 ,000 2% 1% 4% 2% 2% 3% $5-$0,9119 4% 4% 10% 5% 4% 12% $10.$14,1190 6% 5% 9% 11% 6% 11% $15-$10,1190 8% 7% 10% 11% 11% 10% $20.$24,0IHI 8% 7% 8% 8% 6% 9% $25-$29,1190 10% 10% 10% 10% 8% 12% $30.$38,1190 19% 19% 17% 16% 17% 16% $40.$40,900 13% 14% 10% 12% 16% 9% $5o-$50,1190 11% 12% 9% 11% 11% 7% $60,000 or more 18% 21% 13% 15% 19% 11% Source: Household and travel day IRes. When compared to the distribution of households among these same income categories, it is evident that those households with incomes in the range of $15,000 to $40,000 traveled proportionate to their percent share of the total number of households for both Florida (47 percent of the househo lds made 45 percent of the vehicle trips) and the nation (45 percent of the households made 45


57 percent of the trips). However, the lower income households those with incomes below $15,000, traveled much Iess--in Florida, 26 percent" of the households produced only 18 percent of the trips Nationally, 23 percent of the households accounted for only 12 percent of total vehicle trips It is obvious, then, that the additional travel has been produced by those households with incomes over $40,000 Twenty-seven percent of Aor ida' s households were in this lnoome bracket, and those households made 38 percent of all Aorida's veh i cle trips For the U.S., 22 percent of the households made 42 percent of national vehicle trips . Table 1 3 Person Trips By Househol d Location United States Florida '< ;., ... W .> : ,: % Pees Tiij;s' ,.. . ' . . P l\% f H ,,._ MSA. Within Central City 35% 37% 52% 46% M SA Outside Central City 42% 40% 47% 43% Not I n M SA 22% 23% nfa 11% Source : Household and travel day files Table 13 shows the percentage of person tr ips made by locat ion of the household For comparison purposes, the percent distribution of households for these regions is also shown For person trips of travel, households In the suburbs of the nation have been making the most trips; however, the percent of travel was nearly equal to the percent share of total households in those areas. This was a lso true for the


58 central city and non-metropolitan regions, so none of the regions have captured a larger share of the person trip travel In Florida, all of the person trips were generated by households In metropolitan regions, despite 11 percent of the households being located in non-metropolitan regions. No reason could be identified for this occurrence. After cross-tabu lat ing the numerous demographic variables with travel data, travel characteristic variables such as trip mode, vehicle occupancy, and trip purpose were used to analyze and classify the data. Mode choice for making a particular trip was an important travel characteristic that was analyzed at length. One analysis that utilized this factor was the distribution of work commute trips by the primary, or "usual: means of transportation. Acco rding to FHWA, the usual mode signified the means of transportat ion that was used to go to work during the week previous to the interview. Table 14 presents the results of this analysis for Florida and the U.S. Table 14 Distribution of Work Commute Trips By Usual Mode Mode of Tl'llnapoftatlon United Statea Floncg Privately-owned Auto 88% 94% Public Tl'llnapoftatlon 5% Walk 4% 2% Other 3% Source: Person file.


59 In the table, the privately-owned auto category consisted of all cars, householdbased trucks (pickups, etc.), jeeps, and vens. The public transpol1atlon category consisted of buses, trolley buses, elevated rail, and railroads The 'other" category was comprised of taxis, motorcycles, bicycles, and other modes. The percentage data clearly show that autos or related vehicles were the primary mode of choice for making the journey to work. Aorida commuters seem particularly attached to their veh icles, with 94 percent of the workers using this mode for the work trip. Nationally, 9 percent of the tota l commuters utilized public transit or walked to work. This I s twice the percentage that was exhibited by Florida commuters. Unfortunate l y, this extremely high usage of auto in Aorida was perhaps a result of poor transit system services and/or the low density, non pedestrian friendly nature of the state Another important travel characteristic used in a number of analyses was trip purpose. Given the multitude of reasons that people may have to make a trip, the survey questionnaire utilized 11 bas i c reasons in an effort to standardize the responses. Prescribed trip purposes included to/from work, shopping, family or persona l business, social and recreation and vacation, among others. These purposes w ere used in conjunction w ith several other variables to produce informative stratifications of vehiCle and person trip data Table 15 consists of summary vehicle trip data for four mai n purposes: to/from work shopp i ng, other family or personal business, and social and recreation (also includes visiting friends and relatives, vacation, and pleasure driving). Average annual v eh icl e trips, VMT,


60 and average vehicle trip length are presented for each of the four purposes, as well as for all purposes combined, which includes trips made to the doctor, dentist, school, church, and work-relatect travel. Table 15 Summary of Annual Household Vehicle Trip Data By Purpose United States Florida vii :rii>i vi-Ar '' Lgth Veh Trl)l. . ; .,. r "' )h ......... .. : .... .. -, ... ' To/From Work 448 4,853 10.8 400 3,713 9.3 Shopping 345 1,743 5 1 313 1,409 4 5 FamllyfPwtnl 411 3,014 7.3 376 2.321 6.2 Soclai/Recrtn 349 4,060 11. 6 302 2,826 9 4 All Purposes 1,703 15,100 8.9 1,521 11,418 7 5 Source : Tnivel day file. Although Florida households averaged fewer vehicle trips per year than households across the nation, the distribution of trips among the four purposes was nearly identical. Aorida households averaged 1 ,521 vehicle trips per year, which resulted I n 11,418 annual VMT Similar to national characteristics, Florida households made most of their trips to or from work, which produced the highest number of average VMT for any single purpose (3, 713). Trips for social and recreational purposes produced the lowest average for annual vehicle trips in Aorida, but produced the second highest number of vehicle miles traveled. This is why this particular purpose had the longest average trip length of any of the


61 other purposes, 11.6 mnes nationally and 9.4 miles for Florida Both of these distances were longer than their respective total purpose average trip lengths of 8.9 miles and 7.5 miles. In Tables 16 and 17 on the following page, vehicle trips are d istributed by purpose and trip distance for the United States and Florida For the work trip purpose, the majority of vehicle trips were less than 5 miles in length for both study areas. However, Florida vehicle work trips were found to be slightly shorter than those nationally since 85 percent were less than 15 miles In length and only 7 percent were longer than 20 miles. For the U S., 80 percent of the vehicle work trips were shorter than 15 m iles and 13 percen t were longer than 20 m il es. Distr i butions for the other purposes were similar to those of the work trip purpose for both Florida and the nation. In each case, the majority of vehicle trips were less than 6 miles long. Based on percentage distributions, the work trip purpose produced the longest vehicle trips while shopp ing had the highest percent of short trips The rema ining analyses concentrated on the cross-tabulation of the vehicle and person trip/mile data by trip purpose and choice of mode. Original analyses of these data utilized all possible purpose and mode response choices However, since much of the vehicle trip data were m i ssing due to the reason explained previously (respondent must have driven for that trip to be considered a "'vehicle" trip), it was determined that the modes and the purposes needed to be consoli dated in order to fill the data gaps and to simplify the analyses.


62 Table 16 United States Vehicle Trips By Purpose and Trip Distance <8 ml &-10 ml 11 ml 1&-20 ml 21-30 ml >30 ml To{From 44% 23% 13% 7% 7% 6% Work Shopping 76% 14% 5% 2% 2% 1% Social/ 59% 18% 8% 4% 5% 6% Family/ 68% 16% 6% 3% 3% 3% Personal To1al 50% 18% 9% 5% 4% 4% Source: Travel day file. Table 17 Florida Vehicle Trips By Purpose and Trip Distance <8ml &-10 ml 11 ml 1&-20 ml 21-30 ml >30 ml To/From 44% 26% 15% 7% 4% 3% Work Shopping 77% 16% 3% 2% 1% 1% Social/ 68% 15% 9% 3% 5% 2% R-uGn Family/ 70% 17% 6% 2% 2% 2% P-1 Toul 62% 20% 8% 4% 3% 3% Source: Travel day file.


63 Based on a similar oonsorldation reported by FHWA (FHWA, March 1992), the 11 purpose variables were combined into frve new variables: earning a living; family /personal business; civic, educational, and religious; social and recreational; and other. Combining the mode variables was not as straightforward ; because of ll}issinQ data, it was necessary to use two different sets of variables to stratify . I vehicle trip data and person trip data. The two sets of variables did not allow for the calculation of vehicle occupancy rales by purpose and mode slnce thi s rate is calculated by dividing person miles of travel by VMT. Therefore, these rates were calculated from the data using the original purpose and mode variables. Table 18 li sts the various occupancy rates for Florida and the U S. for several modes by the main purposes that were used in Tables 16 and 17. Table 18 Vehicle Occupancy By Purpose and Mode United Stat" Florida .. r. ... "'-.. :::.vtn:;I 1':1-rG\:lr: i)J,;.. ... .. .... :;-: ......... ._ To/From Work 1.09 1.28 1.10 1.09 1.00 1.08 ShOpping 1.51 1.75 1.40 1.42 2.08 1.19 Social/Recreation 1.90 2.79 1 .48 1.73 2.31 1.24 Family/P-I 1 .47 1 .61 1 .32 1.53 2.07 1 .60 Total 1 .46 1 ,83 1 .27 1 .42 1.73 1 .26 Source : Travel day fie.


64 From the data, it was evident that lor both Florida and the nation vans had higher occupancy rates than either autos or trucks. This makes sense given the additional capacity of vans. When households purchase vans, it is so they can transport more people at once, in comfort. It was also evident from the data that social/recreation had the highest occupancy rates of the trip purposes and that the work commute trips had the lowest. One interesting finding from this data was that vans in Florida averaged more than two persons per trip until they were used lor the journey to work. In that instance, the vehicle occupancy rate fell to one person per trip-an obvious waste of vehicle capacity. Using the consolidated mode and purpose variables, person trips lor both the U.S. and Rorida were stratified. The resulting percentage distributions are presented in Table 191or the U.S. results and Table 20 lor the Florida results The data show that auto/van was the dominant mode lor each purpose, both nationally and lor Florida. The school bus mode had a higher utilization for the civic/educational purpose, while walking was an important mode of travel lor civic/educational, social/recreational, and other purposes. Public transit did not capture more than 4 percent of total person trips for any single purpose nationally, and in Florida only civic/educational person trips utilized more than one percent of transit (2 percent). For every purpose but "other: Rorida person trips had either an equal or higher share of auto/van utilization than those of the nation. The percent distribution for the "other" purpose in Rorida was not comparable to that of the nation or to the distribution of any other purpose


65 Table 19 United States Person Trip Dlstrlbutl .on By Purpose and Mode Earn Uving Family/ Personal Civic/ Educational Social/ Olher Recreational Auto/Van 75% 82% 58% 76% 72% Truck 16% 11% 4% 10'lb 8% Pub Transit 4% 1% 4% 1% 2% School Bus 20% 1% Airplane 1% Bicycle 1% 2% 1% Walk 4% 6% 13% 10% 13% Other 1% 1% 2% Total 100% 100% 100% 100% 100% Source: Travel day flle. Table 20 Florida Person Trip Distribution By Purpose and Mode Earn Uving Family/ Civic/ Social/ Other Personal EducaUonal Recreational AutojVan 81% 86% 67% 75% 46% Truck 17% 9% 3% 7% 3% Pub Transit 1% 1% 2% School Bus 17% 7% Airplane Bicycle 2% 2% 13% Walk 1% 4% 9% 14% 30% Other 2% Total 100% 100% 100% 100% 100% Source: Travel day file.


66 Finally, these consolidated mode and purpose variables were use to cross-classify average person trip lengths and average travel times. Average travel times were calculated by dividing total travel times by person trips. The four tables outlining the results follow on the next two pages. Tables 21 and 22 present the average person trip length data for Florida and the nation, and Tables 23 and 24 present the average travel times. Average passenger trip length was found to be the greatest for social/recreational trips (an overall average of 12.94 miles for national person trips and 10.91 miles for Aorida). Not counting airplanes and "other" modes, public tra nsit had the longest overall average trip length (11.76 miles) nationally, while trucks traveled the longest distances in Aorida (10.47 miles). Autojvan trip lengths were relatively long, especially for work and socJal trips; however, both trucks and public transit averaged l onger trips for the nation and, in Florida, trucks averaged long er trips. Analysis of average travel times supports the trip length findings. Again, excluding the airplane and other modes, public transit had the longest overall average travel times for both study areas (34.99 minutes for the U.S., 38.00 minutes for Aorida); trucks (17.52, 20.02 minutes) and autosjvans (15.88, 14.56 minutes) followed distantly. The only difference found in the travel time data was that the overall average travel times for school buses were much greater than the trip lengths would lead one to believe. This is probably due to the constant stops-and-starts that are required of the bus in order to pick up its riders, most of which are schoolchlldren. In fact, the overall average school bus travel times of 20.85 minutes for the nation and 21.37 minutes for Florida placed this particular mode second only public transit in travel time.


Table 21 United States Average Person Trip Length By Purpose and Mode Earn Ulling Family/ CilliC/ SOCial/ Other Personal Educational Recreational Auto/Van 10.83 miles 6.96 6.08 12.72 11.75 Truck 13.11 8.21 6.19 12 .82 10.80 Pub Transit 11.75 9.04 9.24 19.08 17.65 School Bus 8.65 5.18 5 18 21.27 4.00 Airplane 834.58 601.79 824.83 Bicycle 2 .04 1.52 .91 2.37 2.22 Walk .81 .54 .56 .69 1.03 Other 8 .75 10.73 4.42 34.40 4.16 Source: Travel day file. Table 22 Florida Average Person Trip Length By Purpose and Mode Earn Wiling Family/ CiviC/ Social/ Other Personal Educational Recreational Auto/Van 9.19 miles 6 .40 5.70 8.91 2.71 Truck 11.95 8.45 2.88 17.59 3.00 Pub Transit 9.20 1.07 1.66 5.00 School Bus 3.00 7.93 5.25 5 .00 Airplane 1300.00 985.88 . Bicycle 1.75 .51 1.50 1.67 Walk .80 .37 .41 .58 1.09 Other 5.02 7.13 1.00 22.60 Source: Travel day lie.


68 Table 23 United States Average Person Trip Travel Time By Purpose and Mode Eam Uvlng FamUy/ Civic/ Socl81/ Other P8t8onlll Educ.Uonaol RecteatloNII AutojVan 18 .66 mlns 12.96 12.08 20.00 18.79 Truck 21.02 14.00 12.12 19.96 15.88 Pub Transit 40 .55 31.95 30.24 29.82 40.85 SchooiBua 41.51 17.37 20. 47 35.82 12.77 Alrpl8na 205.94 147.46 110 .00 161.14 97.98 Bicycle 15.51 11.09 7.61 14.80 17.66 Walk 9.65 8.34 9.75 11.05 15.79 Other 18.57 19.73 16.73 38.29 6.27 Source: Travel day file. Table 24 Florida Average Person Trip Travel Time By Purpose and Mode Eam Uvlng Family/ Civic/ Soc18f/ Other Penonal Educ.Uonaol RecteaUonaol AutojVan 17.30 mlns 12.58 12.50 16.67 9.44 Truck 22.16 16 .97 8.52 24.30 15.00 Pub Transit 69.05 22.44 18.08 35.00 School a.,. 30.00 13.66 21.84 10 .00 Airplane 450.00 157.53 Bicycle 13.91 5.31 12.96 24.58 Walk 15.63 5.00 8.73 9.32 16 .82 Other 10.06 15.00 59.33 Source : Travel day file.


69 RESULTS: TREND ANALYSIS AND PEER COMPARISON This chapter presents the results of the analyses in which selected 1990 NPTS data were compared to previous years' NPTS data to establish demographic and travel behavior trends for the United States and to current data (peer surveys and data sources) to assess the comparability of the 1990 NPTS results Since analysis of the previous years' user tapes was beyond the scope of this effort, reports and other supplementary documentation for these studies provided by Susan Liss at the Office of Highway Information Management, FHWA, were used as sources for the 1969, 19n, and 1983 survey data. It should be noted that the 1990 population estimate used In this chapter included persons under 5 years old; ratios based on population also used this number. This is different from the estimate used in the last chapter where all data tabulations were based on the number of persons 5 years and older. This change was necessary in order to remain consistent with the 1969-83 data. Trend Analysis Similar to Table 3 in the previous chapter, Table 25 highlights selected demographic and travel characteristics from each of the four NPTS studies. The trends of several of these statistics as measured by the percent change from 1969 to 1990,


Table 25 1969, 1977, 1983, and 1990 NPTS Comparative Statistics .... "" 1883 -"""'nOw .( . . I ; 'ez.SO< 15,412 ' &S;371 I I poon 10.980 18,214 19,354 22.8110 2 JHWeoftl 18,"'8 22,92$ 27,169 30.114 3_. 10 ,74& 13,04& <14,755 4+ JMIMM 22,330 23.227 2<. 082 24.108 foi:.or .. :A IIOft 11:1% 83" 84,. 48"' .,. 4"' 21"' """ .. ,. -6"' -s-. -3 1"' 28,. 38"' 54,. 2 1"' 21"' ,.,. 22,. 22% 31,. 34% 40% 38"' I 84"' I -5811. 48" 33 3a i I 82.r. -llO'!I 7:1% I 85" 701' ".r. Chg, _.column ..-compatal>letrondo (IQ701o 1g&g0f tWO) kom Unllod!itotft: rogr, 111th Ed .. Wuttington o.c., u .s. Bureau ot tn. CMitua. 1Ge1. 'To\11 lnc:fu tetponM& of c:ton'1 know" and 'nM 18ee au..-...y Includes onfy automobiiM, 1wlon wag on and van"'-' ... /mfnibuMI u MI.!MhOicl vehldtt. 'Tho lllee ...,...y doea not h1c:IOOe walk and trlpo Household. petSOn. and 1t8Vel day flies for 1990 data. Summary of Travel Trends: 1990 Natlonwtde Penooal Transpo

71 were compared to trends calculated from data in the 1991 Statlst/Cll/ Abstract of the United States. lhe results showed that the NPTS estimates approximated established national trends quite well. For example, population and the number of households Increased 22 and 47 percent, respectively, according to national data. lhe NPTS trends resulted in changes of 21 and 49 percent for these two variables. Other comparatiVe P.ercent changes are shown in the table; the changes for actual data were based on trends from 1970 to .1990 (1989 when 1990 data were unavailable). It is evident, then that these trends support those outlined at the end of Chapter 2. Growth In households i ncreased at a faster rate than population growth, resulting in decreasing average" household size. lhe percent changes in the age groups confirmed the overall aging of tha population, signaling the maturation of the 'baby boom generation. Greater participation of females In the U.S. labor foroe is clearly evident The inc rease in female employees occurred at a rate over three limes as great as that of the male employees and females' percent share of total employees increased from 36% in 1969 to 46% in 1990. Household vehicle availability also Increased, more than any other major statistic shown The 128% increase in total household vehicles is two -a nd-a-half times greater than the growth in households and six times greater than the population increase. As a resu lt, vehicles per licens ed driver i ncreased f rom 0.70 in 1969 to 1.01 in 1990, and vehicles per worker went from 0.96 In 1969 to 1.40 in 1990. Other changes in household characteristics are presented In Table 26.


72 Table 26 1969, 1977, 1983 and 1990 NPTS Average Household Demographic and Travel Characteristics 1969' 11177 11183 1HO P81'10f1S (.U) per Household 3.16 2.83 2.69 2.56 Ucenaed Drtvera per Household 1.65 1.69 1.72 1.75 Workers per Household 1.21 1.23 1.21 1 27 Vehicles per Household 1.16 1.59 1.68 1.77 Dally Vehicle Trips per Household 3.83 3.95 4.07 4.66 Daily VMT pet' Household 34.01 32.97 32.16 41.37 Average Vehicle Trip Length 8.89 maes 8.34 miles 7.90 m les 8.87 miles tyhe 1969 aurwy indudM only automobiles. ata.tion W1QOM, and VMbuwtjminibuNt u hoUMhold Y'thlcl.._ Source: Household, person. and travel day files for 1990 data. 'Summary of Travel Trends: 1990 Nationwide Personal Transportation FHWA, March 1992, for 1969-83 data. As was expected, household size decreased considerably since 1969. Despite this decline. the average number of both workers and licensed drivers per household inc reased. This seemingly contradictory growth makes sense considering the increase of female workers that, in turn ; increased the number of two-worker households And, as wome n have become employed, they have often i ncreased their mobility by becoming licensed drivers and adding another vehicle to their family's garage. Since 1969, vehicles per household increased from 1.16 to 1. 77 in 1990. More vehicles, drivers, and workers per household also indicate an increased demand for travel. The table reflects this demand, as both daily vehicle trips and daily VMT per household have grown since 1969. The overall growth in VMT resulted from an increasing average vehicle trip length. Despite constant


73 declines between 1969 and 1983, both VMT and trip length increased s i gnificantly from 1983 to 1990. It is believed that the increase In trip length is due to similar increases in the suburbanlzation of the population. This suburbanlzatlon led to increasing trip distances for travelers, specifically for those making the journey to work. NPTS data showed that average commute distances for the home-to-work trip increased !rom 9.9 miles in 1969 to 10 6 miles In 1990. Number of Vehicles No vehicles One vehicle Two vehiclH Tlvee or more vehlcln Table 27 1969, 1 977, 1983, and 1990 NPTS Household Vehicle Availability 19691 1en 1983 12,876 21% 11,538 15% 11,548 14% 30 252 26.092 28,780 48% 35% 34% 16.501 26% 25.942 34% 28,632 34% 2.675 11. 840 16,411 5% 16% 19% 1HO "'Change 6,573 9% -33% 30.654 33% 1% 35,672 38% 117% 18.248 20% 535% Source: Household file for 1990 data. "Summary of Travel Trends: 1990 Nationwide Pe

74 of all households, and two-vehic l e households had I ncreased to a 38 percent share of total. As mentioned previously, this increased vehicle ava i lability along with greater demand for travel has increased the number of trips that househo lds make. Table 28 presents average annual veh i cle trips, VMT, and trip lengths for households each year by trip purpose The data in the table support the identified trends of increased travel and highlight the changes over t i me In trave l for various purposes. Table 28 1969, 1977, 1983, and 1990 NPTS Average Annual Household Vehicle Trip Data By Purpose Trip Purpose 1989 19n 1983 1990 %Change 89-90 To/From Work 445 trips 423 414 448 1% 4,183 m l s 3,815 3,538 4 ,853 16% 9.4 mls 9 1 8.5 10 8 IS% Shopping 213 268 297 345 62% 929 1,336 1 ,567 1 743 86% 4.4 5.0 5.3 5.1 16% Family/Pertnl Bualness 195 215 272 411 1 1 1% 1,270 1,444 1,816 3,014 137% 6.5 6.8 6.7 7.3 1 2% SocllllfRecteatlon' 312 320 335 349 12% 4,094 3.286 3,534 4,060 -1% 13 1 10.3 10.5 11.6 -11% All Purpo..r 1,396 1,442 1,486 1,702 22% 12,423 12 ,036 11,739 15,100 22% 8.9 8.4 7 9 8.9 0% 'Ind.,... trlpo tot IOOialf-.IOioltlng -/rol-o, -and plouuro drMng. trlpo tot -/c:I>UI

75 Since 1969, average annual trip-making Increased for an trip purposes, with trips for famlly or personal business increasing the most. More trips resulted in increased VMT for all purposes except social and recreational trips ; miles traveled for this purpose decreased because of shorter trip lengths. The average trip 'Trgth tor SOCial/ recre ational trips decreased 11 peroent between 1969 and 1990, but increased 10 percent since 1983 perhaps due to the previouslydiscussed suburbanization. Increases in average trip length since 1983 were also evident for work trips and family /personal business trips. Only shopping trips have decreased in average trip length since 1983. This may be attributed to the trend of constructIng supurban malls and retail centers to t ake advantage of the res i dential areas the re. Average vehicle occupancies for these purposes are shown i n Table 29. Tabla 29 1969, 1977, 1983, and 1990 N PTS Average Vehicle Occupancy By Purpose Trip Putpose 19691 1877 1983 1880 To/From Work 1 6 1.3 1.3 1 1 Shopping 2.2 2.1 1.8 1.7 Famlly/Pmnl Bualne11 2.2 2.0 1.8 1.8 Soclai{R-uUon' 2.9 2 4 2.1 2. 1 All PurpOSH' 2.2 1 9 1.7 1 6 %Change 77 % -19% % 13% 16% 'The 1958*"CY.,..,... ,.._lift not dir.c:cty e1not 1M)'..,. beNd on trfpl tot IIU'Iomobls. s&alion "in<*ldft Vlpo fof _,_...,..., vblting frioflds / tolallwt and .,....... ci001/dwldl, doelor/demlot and wi<

76 The occupancy data showed that there were fewer persons per trip in 1990. Overall average vehicle occupancy declined 16 percent, from over two persons in 1969 to just over one-and-ahal f persons In 1990. Trip s for socialjrecreatlonal, shopping, or family I personal business purposes were still being made with an average of two occupants; however, it was evident that a greater percentage of persons we re making these trips alone than they d i d back in 1969 As for the w ork trip, the majority were of the drive-alone variety, a fact that suggests that a significantly smaller share of j ourn ey-to-work trips were being made in carpools and vanpools now than i n 1969 Table 30 examines this d i stribution of work commute trips among the most frequenlly used modes. Table 3 0 1969, 1977, 1983, an d 1990 NPTS Distr ibution of Work Commute Trips By Mode1 Mode ol T ra napootatlon 1968 ren 11113 Auto 82.7% 80.5% Truck' 8.1% 12-li% 14 .8% Public T ranalt 8.4% 4 .7% 5 .8% Olher' .8% 2.3% 1.8% 1880 91 .4%' n/a 5.5% 3.1% 1Mocte ta def!Md u "'""' tt&ntp)rtation us uatl y uMd to g o to work during tnt ._..k befo,. tn.lrne.Mt w 2-"lto and tNdl:.,. oomblned M a WIQM mode in lM 1ggo tuMy. "'na.---""'* p;ckups) excludet. ... .-tPL Source: p.,..,., fie for 1990 data. summary ol Travel Trends: 1990 Nationwide P8t$0031 Transportalion SUIVey." FHWA. March 1 992, lor 1 989dala. The percent distributions among the modes clear1y showed that privately-owned household vehic l es such as cars and trucks were the primary mode of choice for


77 persons commuting to work. Despite maintaining the smallest percent share of total, the use of "other" modes such as motorcycles, bicycles, and taxis increased significantly in the last 20 years. Trips involving public transit, however, decreased as a percent of total, further supporting the decline in vehicle occupancy for this particular trip purpose. In order to Identify the changing utilization of certain modes, a number of crosstabulations were comple ted on the travel data by mode of transportation. Table 31 presents the results from one of these analyses total person trips by mode. Table 31 1969, 1977, 1983, and 1990 NPTS Annual Person Trips (Millions) By Mode' Mode of Transportation 1969 Auto/Van 123.519 Truck" 8,128 School Bus 7,112 Public Transit' 4,935 Other' 1,451 1&dudea utpa made by pertons under 5 years ojd, 'tn

78 The use of autosfvans also continued to increase during this time period. As the modes of choice, autos and vans maintained the largest percent share of total annual person trips despite losing some ground (85.1 percent share in 1969; 82.6 percent share in 1990) to the truck. Of the modes presented, only travel by school bus declined since 1969. This may be attributed to the suburbanization of schools. Proximity to the suburban residential areas allows a greater number of schoolchil dren to walk to school or get dropped off/picked up by a parent. Also, more students of driving age may have had access to autos, exacerbating the decline. Peer Comparison The peer analysis consisted of a comparison of selected 1990 NPTS results to various surveys, fact books, and other current data sources to determine how well these NPTS results approximated data that is accepted and currently being utilized. The peer sources used included Highway Statistics 1989, Statistical Abstract of the United States, MVMA Motor Vehicle Facts & Figures '91, the 1989 American Housing Survey, and the 1988 Residential Transportation Energy Consumption Survey. Depending on the source, comparison data used were from 1988, 1989, and 1990. Because of changes over time in the variables and the relative standard errors associated with the weighted survey estimates, this analysis was not used to evaluate the validity of the data, survey process, or weighting procedures of the NPTS or other surveys. Instead, the peer comparison was utilized as another method to better assess current national demographics and travel behavior characteristics Table 32 presents comparative data for the 1990 NPTS.


2 3 16+ FemaJH Male Foma .. Male Female 16+ .... Table 32 1 990 NPT S and Pe e r s Com par ativ e Statistics 16,128 24,106 114,441 88,432 124,975 54, 328 1,409,576 :231> 6% 2S'J!. 34% 11% 48% 36% 91,6'93 2 52% 127.258" n/a 23% 6'J!. 2S'J!. 33'J!. 12'l!. 49% 37% 51% 40% 1969 19e9 1989 1989 1969 1969 1969 1969 1969 1969 1990 7 9 1 Staflsfka/ Absrtact of the Unifrld Stalet: 1991, tt 1th Ed., Washi n gton, D C U .S. Burau of the Census. 1991, Tablt 60, p. 47. "'l>ld .. Tab l e 22. p. 18 3MVMA Motor Yehle,. Facts & FigutN '91, Otttolt, M l MotOt Vehicle Mal\ufaetu feta Astoda:tlon of the Untted Statea, 1991, f.: 43. S..USfical N>SftOCtofiM Unilld Stoles: 1991, Tab!O 635, p. 386 'HoustlhOid Vehicl.t EMrgy Coneumptlon 1988 Wt.shlngton, D C. Enetgy lnfom\atlon Adminittfation, 1 990 Table 6, p. 28. MVMA Mo1or Vehiclt F .... & F/guros '91, p. !13. Source: Household, person. and travel day taes for 1990 data. Sources fo r peer data are footnoted


80 Despite the availability of 1990 population and household totals (248 7 million persons and 93.3 million households), data from 1989 were used since these data provided breakdowns of households by household size and persons by age and gender. The 1990 NPTS household data approximated the peer data extremely well, both in total and in percent distribution among the household sizes. This was attributed to the fact that 1990 Census data for households were used In the weighting of the survey data to expand the estimates to national totals. The population estimate was low compared to either the 1989 or 1990 totals by nearly nine million persons. Most of the difference occurred in estimates for the under 16 years age category and the 65 years or older category (almost 7 of the nine million). These two age categories were, perhaps, the most likely to receive responses by proxy in the interview process. While the effect of the use of proxy responses has not been determined, the procedure may have resulted in the undercounting of persons. Despite this low population estimate, the distribution of persons within the age groups was nearly identical. The number of licensed drivers for the 1990 NPTS was found to be lower than those in MVMA Motor Vehicle Facts & Figures '91; however, this peer estimate was only an estimate for 1990. Highway Statistics 1989 produced a licensed driver total of 165.6 million in 1989, which showed that the 1990 NPTS figure was still low. The percent distribution by gender did not fare well, either. The 1990 NPTS data showed that females comprised 51 percent of the licensed driver total, while the peer source showed that females comprised only 48 percent of the total. This


81 difference resulted from an underestimation of the number of male drivers. No reason was identified for this. occurrence. The number of workers estimated by the 1990 NPTS exceeded the peer data used. The Cjlifference between the two figures was sli ght, given the orders of magnitude of the totals Nevertheless, the cfiScrepancy may have resulted eecause the peer data only included non-institutional, civilian employees. It was not expected that the NPTS sampled institutionalized persons; however, non-civilian households may have been interviewed. Peer travel data for househo l d vehi cle tr ips, person trips, and person miles of travel were not provided In Table 32. The data from the available sources were not found to be directly comparable to the 1990 NPTS data due to definitional differences in these measures. This problem was also encountered In finding peer estimates of total household vehicles. The number of registered vehicles was available In most sources, but this measure overestimated the number of privately owned vehicles available to households. The 1988 RTECS estimate of household vehicles, therefore, was used. For household VMT, the value used was from MVMA Motor Vehicle Facts & Figures '9 1 and was a preliminary estimate of 1990 VMT for comparable modes. The d i fference between the data may have resulted from the I nclusion of non-household based travel I n the peer VMT estimate. Since the 1990 NPTS estimated household-based VMT, the data may not have captured tourist travel, lease or rental fleet trave l (for purposes other than tourism), or


82 commercial truck VMT (delivery vans, tractor-trailers etc.). Also, work-related travel may have been underestimated for company-owned vehicles used by employees throughout a given work day In addition to national totals of demographic characteristics, selected per household ratios were also compared. Table 33 presents these comparative data. Table 33 1990 NPTS and Peers Average Household Demographic and Travel CharacterlsUcs 1990 NPTS Peer Peer Data Year Persons (all) pet Household 2.56 2.63' 1990 Ucenaed Driven pet Household 1.75 1 802 1990 Worken per Household 1.27 1.26"' 1990 Vehicles per Household 1.77 1.804 1988 Dally VMT pet Household 41.37 50.94' 1988 1$tallstJcaJ Ab$lTact otthtl United 1991, 11111'1 Ed., Wa-st1ing10n, D C . U.S. Bureau of the Cenaua, 1991. Table 56, p 45. 'caic..latod 11om 1990hool-dll&{Sta6stiea/AI>s...,oftllo UnHods-.: 111111. T58. p. 45) and 1990Htlmated tlc:ensecl (lrfVMA Motor v.Ncle Facti & Figuros '91. Oetrol,, Mt, Motor Manutectur..-. Aaaoclatioo of tn. -. 111111 p 43). from 1880 houMhokt and employment data (S.tistic'oll Abft11Ct of r1 Unlttld Sratts: fgff, Table 56, p. 45. and T835. p 38&). 4HouMhokl v.hlcJN EMtVY Con.tuf'J'IPdOn 1988, Washington, D C Energy Information Administration, 1990, 1. p. 31. 'colcuiDclltom &YOtOQO annual hoo!Nhold 1/MT dll& (/b01 .). Source: Household person. and travel day files for 1990 data. Sources lOt peer data are foob1oted. For most measures the 1990 NPTS per household data approximated the peer data very well. The average number of persons per household for the 1990 NPTS


83 was slightly smaller than that of the peer, but this was probably due to the underestimation of persons under age 16 years and older than 64 years that were described previously. The underestimation of male ficensed drivers also affected the licensed drivers per household measure. Daily household VMT was the only measure that produced any significan t difference between the NPTS data and the peer data. Since the peer average was cal culated from the 1988 RTECS estima te of annua l household VMT, the difference may have been related to the standard errors associated with each survey Econom i c conditions may have also red uced average VMT per household. Finally, household vehicle availability was analyzed in the context of peer data Table 34 highlights the comparison of household distribution among the number of vehicles avai l able for both the 1990 NPTS and the 1988 RTECS surveys Table 34 1990 NPTS and Peers Household Vehicle Availability Number 01 Vehlclft 18t0 NPTS p-No vehlclft II" 13% One vehicle 33% 34% Two vehicles 38% 36'!(, Three or more vehicles 20% 16% P-DaUIYaat 19881 --Vhlolol Ent111Y ConOUI7lplk>n 1g98, Wuhi<1glon, D.C., Enorgy Information Admlnl.,.llon, IGGO. Toblo 7 p 31. Source: Household file for 1990 dll18. Source for peer da1a is footnoted


84 The distributions proved to be somewhat similar except that the NPTS data had higher percent shares of households with two or more available vehicles and a corresponding decrease in households with no vehicles. This distribution may have resulted because of the survey methodology used: the telephone interview. It seems likely that there was a strong correlation between vehicle availability and not having a phone. As was mentioned previously in the third chapter, RTI's weighting procedures took this aspect of the survey methodology into account; however, it was possible that it was not corrected for adequately. As a result, not sampling households without phones may have lowered the percent share of zero vehicle households. Another possibility is that the surveys' re lative standard errors may have had some effect on the data. Finally, the differences may have actually been due to the trend of increasing vehicle ownership. Table 27 reflects this trend uslng household vehicle availability data from the four NPTS surveys. It was evident that the number of households with two, three, or more vehicles increased as a percent of total over time. As such, the 1988 RTECS data more closely approximated the percent distribution of the 1983 NPTS survey, and the difference in the 1990 data may be explained by increased vehicle ownership and the passage of time between the two surveys.


' '.' 85 SUMMARY AND CONCLUSIONS The analysis of the results of the 1990 Nationwide Personal Transportation Study was undertaken in an effort to gain insight into and a better understanding of tne influences on current travel behavior and demographic characteristics in Florida and the United States. Current transportation data has always been Important to planners, forecasters, and policymakers making the NPTS survey findings an invaluable source of information. The presence of comparative data bases such as the 1990 Census and its Journey-to Work component have made the demand for the 1990 NPTS results even greater. This research effort, therefore, sought to capitalize on the availability of this recent, comprehensive data base to analyze present day transportation characteristics and develop an overall picture of travel today The analyses conducted on the 1990 NPTS data base included a comparison of tabulated data for Florida and the United States, an examination of the trends described by the data from this survey and its predecessors, and a comparison of the results to recent findings from other peer surveys and data sources The first analysis was the most extensive and was conducted to determine and understand differences In travel behavior that exist between Florida and the nation. Differences that were identified were then evaluated in terms of the underlying


86 contributing factors and implications. The trend analysis was conducted to highlight the changes that have occurred over the last twenty years in travel and in person and household characteristics. This analysis also enabled the evaluation of how well the NPTS data represented known trends that have been established in other data sources Simi l arly, the peer comparison analysis of t he 1990 data was undertaken to assess the findings in terms of currently accepted data from other recent sources of information. This procedure was conducted only to enhance the understanding of the results, not to critique the NPTS data's validity or the survey methodology. In analyzing the data, several d i fferences in socio-economic and travel characteris tics between Florida and the nation were identified. Despite Florida having slightly smaller households on average, both study areas were found to primarily consist of two-person households. Annual household income was in the range of $30$40,000, with both household members bei ng licensed drivers and workers. Each member had a vehicle available that was primarily used for transportation tojfrom work. Florida households made fewer daily trips than did national households and those trips were consistently shorter in length, regardless of trip purpose. This behavior resulted in Aorida households traveling significantly fewer vehicle miles per year. When they did travel, Floridians rel ied primarily on the automobile or van-the same mode of choice for national househo l ds. Persons In both study areas also preferred to drive alone, especially for the journey to work.


87 One of the most significant findings of the household data was that of Rorida's shorter average household vehicle trip length. T.hls finding has several Implications related to suburban development, viable mode choices, and potential transporta tion demand management (TOM) measures. Rorlda's development patterns have often been described as sprawled;" however, with average trip lengths shorter than those of the nation, it seems likely that this i s not the case. Instead, jobs, businesses, and retail centers may have kept pace with development and have helped to shorten F lorida 's trip lengths by decreasing the number of long commute trips to the central cities for work and other purposes. Shorter trips also affect potential mode choices for Rorida metropolitan areas. Commuter rail, a mode whose value is pred i cated on long commute trips, may not be a viable mode choice in some areas. Bus transit may also be affected due to the current I nability of many Florida systems to prov ide effective service for short Jntrasuburban trips. In addition, the Incentives for utilizing TOM alternatives such as park-and-ride lots and carpools j vanpools lose the i r value when the short trip l engths reduce the measures' effectiveness. At the person level, both Florida and the nation had slightly more females than males, and the predominant age group was 20-34 years old. Rorld!i'S population was found to be older than that of the nation. More men w011
PAGE 100

88 durin g this t i me period. Women made sligh tly more average daily person trips than men did but their t ri ps were much in len gth. This resulted in w omen traveling fewer annual person miles, on average, than men. Men, however, were found to make more average daily veh icle trips, signifying that they drove more often than wome n The trend analysis sho wed that the N PTS data reflected established trends rather well The data captured known changes such as increasing female participat ion in the work f orce, the aging of the population, the decreas ing average size of households and the increasing availability of vehicles to househo l d members Changes in trave l characteristics were also reflected by the da t a from th e f our NPTS surveys: increasing vehicle trip lengths potentially due to t he increased suburbanization o f the nat i on's population, the decrease in average vehicle occupan cies exacerbated by the drive a l one wo rk commute, and the decreasing utilization o f transit to make the journey to work In most of the cases I n wh ic h comparab le peer data was ava ilabl e the 1990 NPTS results approximated the peer data rea sonab ly well. In several instances, most notably total population and its distr ibution by age and gender the m eas ure totals were different yet th e percent d istributions among the selected constituent parts were nearly id e ntical. Favorab l e comparisons were also id e ntified for sev erai average household characteristics such as household size and the number of workers per household. Some of the differences that were identified between the

PAGE 101

89 NPTS data and the peer data could be logically e xpla ined in terms of changes over . time, such as for the corriparison of household vehicle availability. Other discrepancies could only be assumed to result from differences in the measure definitions or data collection procedures used by the different data sources. Nevertheless for the selected measures that were able to be compared to peer data, the overall results were favorab le. In conclusion, th e 1990 NPTS was corresponded with identified data measures and trends (in conjunction with the previous N PTS surveys) that were reported in other sources. These results in creased the credibility of the other NPTS findings that were not compared to peer data. Wrth this data base, then, it was possib l e to construct an overall picture of travel behavior and demographic characteristics in both Florida and the United States that quantified curren t-da y person, household, and travel conditions. A dditio nal Resear ch The first opportunity for additional research exists in the wealth of information afforded by this data base Due to the voluminous size of this data base, it was not possible to analyze all of t he available variables in this research effort. NPTS data that was not analyzed includes extensive accldent data, specific travel characteristics for travel period trips (greater than 75 miles in l ength) vehicle specific data such as vehicle age and make, family lif e cycle data (household status by number of adults, number of children and their ages, and retirement

PAGE 102

90 status of the adults), and the education level of the respondents. Other items for Mure analysis efforts include the effect of household location on travel, the effect of urban area size or metropolitan statistical area (MSA) size on household characteristics and travel, and the Impact of congestion on commuting for work or other purposes. The NPTS data base could also be used to conduct more in-depth analyses of specific population segments. Trip-making characteristics for the elderly, for example, could be analyzed in current-day terms as well as over time. Changes in person trips and miles traveled for this age group may have had an impact on total travel or the congestion that many travelers are currently experiencing, especially in Aorida where the elderly comprise a larger percent share of total population than they do nationally. Similarly, additional analyses could be undertaken on the travel made by teenage drivers and the effect that the increasing availability of household vehicles has had on this particular age group O.e., the relation to the decline in school bus use). Travel characteristics of females could also be further analyzed, especially i n the context of the change in travel behavior for working women versus non-working women Analyses of female travel by mode and purpose may also provide insight into the reasons why women were found to make more average daily person trips than men (3.12 trips for wome n vs. 3.03 trips for men), but traveled significantly fewer average daily person miles (25.83 miles for women vs. 31.56 mnes for men).

PAGE 103

. 91 Other potential In-de pth analyses of results from this effort include the determination of why average daily vehicle trip lengths in Florida were shorter than those nationally, the analysis of the relationship between trip lengths and vehicle occupancy, and the analysis of the relationship between travel times/speeds and the age and gender of the driver. In Florida, the average daily vehicle trip length for households was found to oa 7.51 miles, nearly one-and-one-half m i les shorter than the national household average (8.87 miles). Further analyses of trip lengths by age, gender and purpose could highlight reasons for this difference, especially if Florida's older population is affecting the average trip length because of their traditionally shorter trips. Also, this trip length difference may be affecting the vehicle occupancies found for Florida trips. As mentioned previously it seems likely that shorter trip lengths discourage vanpools, and other higher occupancy modes so analyses of occupancy and trip length by age and gender could provide Ins ight into this relationship and possibly identify reasons for Florida's lower vehicle occupancies. Additional l y the effects of age and gender on travel times and speeds could also be analyzed to establish the relationship betweel) these factors. Further analys is may reveal other reasons for Florida's lower trave l times besides the obvious effect that shorter trip lengths have had on this measure. Fina l ly, an opportunity for additional research can be found in the 1990 Census' Journey-to-Work component. Since this data base was not available at the time of t his research, it was not analyzed i n comparison t o the NPTS findings. The

PAGE 104

92 Journey-to-Work data is another beneficial transportation data source that could serve to further enhance the demographic and travel framework established by the NPTS data and its peer sources. The Aorida NPTS review would also benefrt from the presence of state-level Census data since the findings would then have a current data source against which to be compared In the Mure, Florida may consider funding additional surveys in the subsequent NPTS effort to increase the sample size of its respondents and supplement its travel data base.

PAGE 105

93 LIST OF REFERENCES Alqerson, Stephen R. "Minneapolis-St. Paul Metropolitan Area 1990 Travel Behavior Inventory.' Paper presented at Transportation Research Board, 70th Annual Meeting, Washington, D.C., January 1991. Apogee Research, Inc. "Trip National Transportation Survey: 1990 Poll Results." n.p., Apogee Research Inc 1990 Bureau of Economic and Business Research. Florida Statistical Abstract: 1991. 25th edition (and previous), Gainesville, FL, University Press of Aorida, 1991. Center for Urban Transportation Research. "Factors Related to Transit Use: Tampa, FL, Center for Urban Transportat ion Research, 1989. Energy Information Administration. Household Vehicles Energy Consumption 1988. Washington, D.C., Energy Information Administration, Department of Energy 1990. Federal Highway Administration. Characteristics of 1977 Ucensed Drivers and Their Travel: Report No. 1, 1977 Nationwide Personal Transportation Study. Washington, D.C., Federal Highway Administration, October 1980 . Purposes of Vehicle Trips and Travel: Report No. 3, 1977 Nationwide ---=Personal Transportation Study. Washington, D.C., Federal Highway Administration December 1980 . Vehicle Occupancy: Report No. 6, 1977 Nationwide Personal Transpor ---,.tation Study. Washington, D.C Federal Highway Administration, April 1981 Household Travel: Report No 9 1977 Nationwide Personal Transporta --_,.,tion Study. Washington, D.C. Federal Highway Administration, July 1982 . Summary of Travel Trends: 1983-1984 Nationwide Personal Transporta --..,.,tion Study. Washington, D.C., Federal Highway Administration, November 1985.

PAGE 106

94 --'----,. Survey Data Tabulations: 1983-1984 Nationwide Personal Transportation Study. Washington, D.C., Federal Highway Admin istration, November 1985. ----,. Personal Travel in the U.S.: 1983-1984 Nationwide Personal Transporta tion Study. Vol. II, Washington, D.C., Fe deral Highway Administration, November 1986. ---, Journey-to-Work Trends Based on 1960, 1970, and 1980 Decennial Censuses. Washington, D.C., Federal Highway Administration, July 1986. --....,. Highway Statistics 1989. Washington, D.C., Federal Highway Adminis tration, 1990. 1990 Nationwide Personal Transportation Study: Early Results. Washington, D.C., Fede ral Highway Administration, August 1991. 1990 Nationwide Personal Transportation Survey User's Guide for the ----;:Public Use Tapes. Washington, D.C., Federal Highway Administration, November 1991. Summary of Travel Trends: 1990 Nationwide Personal Transportation ----;:Survey. Washington, D.C., Federal Highway Administration, March 1992. ---. 1990 Census Transportation Planning Package Application. Census Application Workshop notebook, May 1992. Gordon, Peter, Harry W. Richardson, and Myung-Jin Jun. "The Commuting Paradox, Evidence from the Top T wenty." Journal of the American Planning Association Vol. 57, No. 4, Autumn 1991, pp. 416-420. Hartgen, David T. 'Transportation Myths: Travel Behavior, System Condition, and Land Use." Paper presented at IBM Technical Symposium: Vision for the '90s, Charlotte, NC, May 1990. Highway Users Federation 1989 Highway Fact Book. Washington, D.C., Highway Users Federation and the Automotive Safety Foundation 1988. Institute of Transportation Engineers. ITE Mobility Facts. Washington, D.C., Institute of Transportation Engineers, 1992. Lave, Charles. 'Things Won't Get a Lot Worse: The Future of U.S. Traffic Congestion. Irvine, CA, Institute of Transportation Studies, University of California, 1990.

PAGE 107

95 Market Strategies, Inc. "Transit NOW National Public Opinion Survey on Transportation Issues and Pollcles, Summary of Findings." n.p. America's Coamion for Transi t NOW, 1991. Motor Vehicle Manufacturers Association of the United States, Inc. MVMA Motor Vehicle Facts & Figures '91. Detroit, Ml, Motor Vehicle Manufacturers Association of the United States, Inc. 1991. "Nlpionwide Personal Transportation Study Data Released. The Urban Transportation Monnor, September 27, 1991, pp. 2,6,9. "Personal Transportation Data Show Mobility Rate Soars." Land Use Digest, Vol. 24, No. 11, November 1991. Pisarski, Alan E. Commuting In America: A National Reporl on Commuting Patterns and Trends. Westport, CT, Eno Foundation for Transportation, Inc., 1987. Prevedouros, Panos D., and Joseph L. Scholer. "Suburban Transport Behavior as a Factor in Congestion." Transportation Research Record 1237, Transportation Research Board, Washington, D.C., 1989 pp. 47-58. Purvis, Charles l. "Survey of Travel Surveys II." Presentation at Transportation Research Board, Mid-Year Meeting and Conference, Transportation Data and Information Systems, October 1989 Rodenborn, Shirley A., and Charles L. Purvis. "1990 Bay Area Travel Surveys: Data Collection and Data Analysis." Paper presented at Transportation Research Board, 70th Annual Meeting, Wash ington, D.C., January 1991. Sharn, Lori. "Drivers Traveling More M ile s ." USA Today, October 18-20, 1991, pp. 1A,5A. Smith, Frank A. Transportation in America: A Statistical Analysis of Transpottatlon in the United States. 9th edition and supplements, Westport, CT, Eno Transportation Foundation, Inc., 1991. Sosslau, Arthur B. Model Related Uses of Census Data for Transportation Planning.' Transportation Research Record 981, Transportation Research Board, Washington, D.C., 1984, pp. 70-81. u.s. Bureau of the Census. Statistical Abstract of the Unned States: 1991. 111th edition, Washington, D.C., U.S. Department of Commerce and B ureau of the Census, 1991.

PAGE 108

96 U.S. Department of Housing and Urban Development. American Housing Survey for the United States in 1989. Washington, D.C., U.S. Department of Housing and Urban Development, U.S. Department of Commerce and Bureau of the Census, 1991. U.S. Department of Transportation. "lntermodal Surface Transportation Efficiency Act of 1991. Washington, D.C., U.S. Department of Transportation, 1991. =-.::-,.. Characteristics of Urban Transportation Demand: An Update. Washing ton, D.C., Urban Mass Transportation Administration, July 1988. Wheeler, William, and Carter Brown. "Metropolitan Transportation Authority: Comprehensive Travel Telephone Survey.' Presentation at Transportation Research Board, 70th Annual Meeting, Washington D.C ., January 1991.

PAGE 109


PAGE 110

APPENDIX A: 1990 NPTS S URVEY QUESTIONNAIRE THE 1990 HATIOHWIDE PrRSOHAl T_.HSPORTATIOH SURVEY (NPT$) QUESTIONNAIRE MAIN SURVEY VERSION OH8 No, 2125-0545 Expires: 1/31/93 U nited States Department of T ransportation Contrct DTFH61C Expiration Ot 9/30/91 Rele&rch Trian9lt Jnstftyt P.O. lox 12194 R e search Tri .ng l e Park, MC 27709 July 29, 1990 ::, "-g..: f'ts.tK-"'11 Nngre-277()g.2194 98 Toloonone 9 : ? F u : 919 S.1 8 Coclt RESTRINS, Roloogh, NC TeiPI02509 (RTI RTPI()

PAGE 111

Appendix A. (Continued) 99 THE 1990 KATIONWIOE PERSONAL TRANSPORTATION STUDY QUESTIOKNAIRE MAIN SURVEY VERSION lLPHOHE NUMBER SCREENING QUESTIONS Hello. my name is I am calling from the Research Triangle Institute, a non-profit research fina in North Carolina. 1. I am trying to reach (NUMBER). Did I dial the correct I YES > GO TO ITEM 3 2 NO 3 LANGUAGE BARRIER ---> THANK RESPONDENT; H4NG UP 2. 1 reache6? NUMBER:-----. INTRYIWR: IS THIS TH SECOND TIHE YOU HAYE REACHED THIS SAHE WRONG HUMBER? I YES 2 NO J ---> THANK RESPONDENT; HANG UP J. we are conducting an important study for the u.s. Department of Transportation, an agency of the Federal We are calling a ra ndom sa m ple of telephone numbers and I need to know what type of number this ts. Does it a home, a business, or something else? I HON ---> GO TO JTH 6 2 SUSitlESS/INSTITUTION 3 "' OTHR 4. Does anyone live there on the pre D ises? I YES 2 HO > lH.HK RtSPOHOEKl; HAHG UP 5. Is this the number they use as their home phone? I YES Z HO > !HANK RESPONDENT; HANG UP 6. Is th1s telephone number just for (your/one) household or does it also serve IS the home telephone nuaber for people in other households as well? I SERYES ONE HOUSEHOLD > GO 10 ITEM 8 2 SERYES MORE THAN ONE HOUSEHOLD

PAGE 112

Appendix A. (Continued) SCREENING (Continued) 7. Can you tell me the total number of houSeholds served by this telephone number? NUHSER OF HOUSEHOLDS SERVED: ----Row, I would like to talk about your household only. 8. Oo ten or more persons currently live in this household? I YES 2 HO > GO TO ITEM 10 9. Are any of these p ersons related#to each other? I YES 2 NO > G O TO ITEM 13 100 10. Are there other telephone nucbers for this home on which you could also be ru:hed? I YES 2 NO GO T O ITEM 12 Il. How aany different residential numbers, including t his number, are there for your household? HUI GO T O HOUSEHOLD QUESTIONNAIRE 2 HO > ASK TO SPEAK TO A HEHBER 18+; IF HONE AVAILABLE. HAKE ARRANGEMENTS FOR CALLBACK. WHEK AVAILABLE, COHTINUE WITH HOUSEHOLD QUESTIONNAIRE. 13. That is all of the q u estions 1 have. I want to thank you very much for your help in this study. Have a good (evtning/day).

PAGE 113

Appendix A. (Continued} QUESTIONNAIRE: $ECTION A INTRODUCTION INTRODUCTION FOR USE WITH HOUSEHOLD RESPONDENT (Hello, my nm is I am calling from Research Triangle Institute, a nonproflt research firm in North Carolina.) We are conducting the Nationwide Personal Transportation Survey for the U.S. Department of Transportation. The results will be used for future planning of roads and other transportation n eeds. All fnfonaation will be used for statistical only. Participation is voluntary. However, your household has been selected to represent others in your community and your cooperation is extrecely important. (NOTE: IF RESPONDEN T ASXS WHO AUTHORIZED THE STUDY, YOU SHOULD TELL THEH IT HAS BEEN AUTHORIZED BY T I TLE 23, UNITED STAT(S CODE.} GO TO SECTION B. tLLBACK FOR HOUSEHOLD MEMBERS OTHER THAN HOUSEHOLD RESPONDENT: Hello, my naQe is I am calling from Research Triangle Institute, a nonproftt research finn in North May I speak to (HOUSEHOLD H.EKBER)? I AVAILABLE > CONTINUE; REINTROOUC YOURSELF AS NECESSARY; 2 NOT AVAILABLE .> !lAKE ARRANGEMENtS FOR CALLBACK. INTERVIEwER: IS THIS A PROXY INTERVIEW? I YES Z HO HAS PERSON YOU ARE SPEAKING TO BEtH PREVIOUSLY INTERVIE11ED? I YES > GO TO SECTION E 2 NO > CONTINUE (Hello, 41 name i s 1 am CAll ing from Research Triangle Institute, a non-prof, t research f1na in North Carolina.) We are conducting the Nationwide Personal Transportation Survey for the U.S. Department of lransp ortatio n. The results will be.used for future p lanning of roads and other transportation needs. All information will be used for stltisticll purposes only. Participation is oluntary. However, your household been selected to represent others in your and your cooperation is extremely important. [NOTE: IF RESPONDENT ASKS WHO AUTHORIZED THE STUDY, YOU SHOULD TELL THEM IT HAS BEEN AUTHORIZED BY TITLE 23, UNITED STATES COOE.) GO TO SECTION E. 101

PAGE 114

' Appendix A. (Continued) SECTION 8 DATA (HOUSOOLO RESPONDEKT) Ffrst. [would lfke to ask you soee questions a bout v eh;eles owned or used by the household. 1. How licensed vehicles wert owned, or available for regular use by embers of thfs household durfn9 the past two weet1t [PROBE: Include leased or licensed .atorfttd vehicles tf they are used by household embers on 1 re9ular basis. Also include HOPEOS (ootoriztd bicycles) whethtr licensed or not.] ________ HUHSER OF VEHICLES > IF NON, GO T.O NEXT SECTION IF HOA TKAK ONE, SAY: I have a few questions about each of these vehicles. Let's surt tf"tth the ntwtst one. 2. typo o h! c l e i s (I t / tho ntxt one) ? PROBE FOR SPECIFIC TYPE; READ CKOIC!S AS NECESSARY. 0 1 AUTOMOBILE (I N C L UDING STATION VAGOH) 02 PASSENGER VAN 03 CARGO VAN 04 PICKUP TRUCK (JNCLUOIHG PICKUP CAMPER) OS OTHER TRUCK 06 RY OR MOTOR HOM[ 07 MOTORCYClE 08 HOPED (MOTORIZED BICYClE) 09 OTHER (SPECIFY) CHECK ITEH: IS CODE 07 OR CODE 08 OR CODE 09 ENTERED IN QUESTION 2? 102 I YES > GO tO QUESTION 5 2 NO >CONTINUE WITH QUESTION 3 3. is tht DOdtl yur? YEAR: ----(. Whit is the kt 1nd model ? FORO. ESCORt; C HEVROLEt, BERETTA; HONOA. ACCORD; HISSAH, SHHZA] HOOEL: ----5. I s tht Ythiclt owntd by 1 ...Oer of tht household? I YES > GO TO QUESTION 7 2 HO

PAGE 115

Appendix A. (Continued) srct1on b (con t inued) 6. Is the vehicle .. 1 (a.pany-owned1 2 leased l rented or 4 u sed under sa.. other & rrangr.entf (SPECIFY) 1. Wts tht vthiclt purchsed,or receivtd, in the past 12 .onths; that is, s ince (HONTH/YEAR)? I YES 2 NO > GO TO O UESTION 9 a. In what onth and year was it purchased or received? MONTH YEAR ---9. Vts tt ne-or u se d whtn it wts bought, or received? I KEV 2 USED 103 10. About how man y miles was this vehfclt drten [durin9 the last 12 conthS/s I nee (HOriTH/YEAR BOUGHT OR RECEIVED))? Include all tape drl ven by 11\ drlvus. M ILES CHECK AltO, IF NECESSARY, CORRECT MilEAGE ENTERED RETURII TO OUESTIDK 2 AND OBTA!H INFORH.ITIDK OH THE HEXT VEHICLE UHTil IKfOJU'-"TIO HAS BEEN OBTAINED FOR All HOUSEHOLD VEHICLES.

PAGE 116

Appendix A. (Continued) SECTIOM C AVAILABILITY Of PVIL!C (HOUSEHOlD RSPONDtNT) Mow 1 1fke to 1sk about public transportation in the 1. Is public transportation to (you/your household)? (PAOBE: Publ;e tran1portatton includ es bus servict, train servfc.e, streetcar, subway, and tltvattd rail.) I YES 2 NO } 98 DON'T KNOW -> GO TO NEXT SECTION 99 REFUSE 2. How far is it froa your homt to the nearest public transportat ion stop7 READ AS NECESSARY. 104 1 LESS THAN 3 ILOCKS (LESS THAN ONE-FOURTH Hll) 2 3 BLOCKS (ONEFOURTH"TO ONEHA lF Hll) 3 7 BLOCK S (MORE TNAH OHEHALF MILE IUT HOT MORE TNAH ONE HIL) C 13 BLOCKS (MORE THAll ONE MILE BUT HOT MORE TNAH TWO MILES) 5 MORE TNAH 2 MILES

PAGE 117

' Appendix A. (Continued) SECTION 0 PERSON DATA fOR EACH HOUSEHOLD MEM8ER (ROSTER) {HOUSEHOLD R ESPONDENT) Mow t would like to ask couple of questfons about each person in this household. 105 1. How peoplt l ive in this household? Please include anyone living staying there now, such as friends, relat ives, or boarders, and anyone who usually lives there but is now away from home such as traveling1 or in the hospital. Do not include anyone who usually lives so.ewhere else. TOTAL NUI18ER: -----2. What is t h e first name of (the person, or one.of the persons, who owns or rents the home/the next person who lives tbere)l [PROBE: We are not colle
PAGE 118


PAGE 119

Appendix A. (Continued) 107 The (first/next) questions deal with (your/PERSON's) UJual or .. i n actiwi t y. 1. Khat (were you/was PERSON) doing oost of last week working, keeping house, going to school, or doing SODethingliTser-"REAO ANSWER CHOICES AS NEEDED. I WORKING > GO TO QUESTION 4 2 WITH A JOB BUT NOT AT WORK > GO TO NEXT SECTION 3 LOOKING FOR WORK 4 XEEPIHG HOUSE S GOING TO SCHOOl 6 UNABLE TO HORX > GO TO NEXT SECTION 7 REliREO 8 (SPECIFY) --------------2. Ofd (yo u/PRSOH) do any wort l!!! week. not co"nting wort bcuse! I YES > GO TO QUESTION 4 2 NO 3. Ofd (you/PERSON) havt a job or business from which (you wert/PERSON was) absent last wee\7 YES) 2 NO > GO TO NEXT SECTION 4 How did (you/PERSON) gtt to work LAST WEEK? ENTER ALL THAT APPLY. 01 CAR, TRUCK, JEEP, OR VAN 02 SUS OR TROLLEY BUS 03 STREETCAR OR TROLlEY CAR 04 SUBWAY OR ElEVATED OS RAILROAD 06 fERRYBOAT 07 TAXICAB 08 llTORCYCLE 09 BICYClE 10 WAlKED II OTHER (SPECIFY) CHECK !TEll: I S MORE TlWI ONE AliSVER ENTERED IN QUESTION 4? I YES > CONTINUE Z HO > GO TO NEXT CHECK ITEM

PAGE 120

Appendix A. (Continued) 108 section e (continued) 5. What w4s the main means of transportation (you/PERSON) used to get to work las t week; that is, the one used for most of the distance? 01 CAR, TRUCK, JEEP, OR VAN 02 BUS OR TROLLEY BUS 03 STREETCAR OR TROLLEY CAR 04 SUBWAY OR ELEVATEO OS RAILROAD 06 FERRYBOAT CHECK ITEM: IS Q.4 OR Q.S RESPONSE COO 01? 07 TAXICAB 08 HOTORCYCLE 09 BICYCLE 10 WAlKED II OTHER (SPECIFY) I YES > CONTINUE 2 HO ->GO TO SECTION F. 6. Do you pay for park1ng at work? I YES 2 NO J 98 0011' T KNOll > GO TO NEXT SECTION 99 RtFUSE 7. How =uch do you usually pay? [liTER AMOUNT: S ----IF HOllE, ENTE R 00; CAT! WILL SKIP TO HUT SECTION. ENTER COO FOR TIME PERIOD: I HOUR 2 PER DAY 3 PER WEEK 4 PER IIJNTH S OTHER (SPECIFY) ------

PAGE 121

' Appendix A. (Continued) SECTION f DRIVER INfORMATION (HOUSEHOLD MEMBERS 16 YEARS OR OLDER; PROXY PERMlllED) 109 I. IF PERSON HAS lHDICATEO THAT HE/SHE DRIVES, VERIFY AHO ENTER CODE WITHOUT ASKWG: (Are you/ls PERSON) 1 licensed driver? I YES Z HO > GO TO HEXT SECTION 2. Kow old (were you/was when (you/he/she) began driving on public roads? AGE:---CHECK ITEM: DOES E1 OR EJZ? 1 YES :> GO T O Q7 Z HO > COHTIHUE 3. Except for getting to and from work, (do you/does PERSON) drive a licens e d motor vehicle on a daily or regular basis as an essentia l part of (your/PERSON'S) work? [PROSE: mean people such as cab drivers, truck drivers, and delivery people who must dr;ve to perform their work,] 1 YES Z HO > GO TO QUESTION 7 4. type of vehicle is that? If MORE THAN ONE TYPE, MARK THE TYPE MOST CFTi:N READ AHSWER CHOICES AS NECESSARY. 01 AUTO (INCLUDE STATION WAGON) 02 PASSENGER VAN OJ CARGO VAH PICKUP TRUCK (INCLUDE PICKUP WITH CAMPER) OS OTHER TRUCK 06 RV OR MOTOR HOME 07 MOTORCYCLE 08 HOPED/MOTORIZED BICYCLE 09 OTHER P.O.V. (SPECifY) 10 BuS 11 TAXI (COMMERCIAL USE) ZO SCHOOL BUS Zl OTHER (SPECIFY) s. On the average, how many days a w ee k (do you/doe s PERSON) drive as a part of (your/his/her) work? --DAYS A WEEK 6. Ouring an average week, what is the total number of miles (you drivt/PERSOH drives) as part of (your/his/her) work, not counting miles driven to and from (your/his/her) place of work? ---HILES

PAGE 122

Appendix A. (Continued) 110 7. [Includin9 the elles driven as '" essentil part of {your/his/her) work) about how .. ny lles did (you/PERSON) personalty drive during the past IZ months? Include mileage driven in all licensed .otorfzed vehfclts. ____ HILES INTERVIEWER: CHECK AND, IF NECESSARY, CORRECT MILEAGE ENTRED.

PAGE 123

Appendix A. (Continued} 111 Now I >Ou l d like to ask about any trips of 75 ailes or DOre one way that (you/PEASON) ay have taken that ended during the p e r iod to ---( 1 4 DAY TRAVEL PERIOD). If QUESTION E-8 OR QUESTION E IS 'YES', SAY1 In telling me about trips of 75 ailes of aore froe home, do not include trips (you/PERSON) eade as an essential part of (your/his/her) !2!! I. !eforo (14 DAY P[l!IQO START DATE). did btgin a trip of 75 lies or 110rt ou wa:y fr whic h (you/ht'/sbel returned hOM bet'Wten and ? I YES 2 HO 2. Oid (you/P-Eii.SOrt) begin a trip bttwetn =cr-=:::...:travel 75 111.fles or one way, and return hoae b etween and 7 I YES 2 NO CHECK [T(ll, If 'NO' TO BOTH I AIID 2, GO TO NEXT SECTION. I f "YES" TO EITHER-r"OR 2, CONTINUE. 3. How many trips of 7S afles or more one way did (you/PERSOK) take where (you/he/sht) returned home between and ? ____ TRIPS If GO TO N!XT SECTION 4. Wha t w&s tht frthast point (you/PERSON) trveltd to on (this/the first/tbt next) trfp? Plta se tell ae the city and st1te or foreSgn tountry. CITr OR PlACE --STATE OR FOREIGJI COUNTRY ----

PAGE 124


PAGE 125

' Appendix A. (Continued) 113 section g (continued) 9. ASK ONLY If Z OR MORE PERSONS LISTED ON HOUSEHOLD ROSTER: Were any household members w ith (you/PERSON) on the trip to (OESTINATIOH)l I YES Z NO > GO TO QUESTION II 10. Which household members? [PROBE: Any other household m embers?] ENTER ROSTER NUMBER(S): ----------. 1 1 Old any n on-household m embers go with (you/PERSON) on this trlpl I YES 2 NO .> GO TO VE.RIFICATJ(Nj 12. ROOf many non .. hou.sthold aettbtrs wtnt on U1h trip with {y.ou/PERSOM)l !MOilER: ---YRJFICATJOH: So there (wts one person/were p ersons) on this trip? VERIFY THT THE SUM OF ENTRIES IH ITEMS 9 THE RESPONDENT I S THE TOTAL NUI CONTINUE 2 NO > GO TO QUESTION 18 14. 11/.RX "NO" WITIIOUT ASKING IF KO YtlllClES REPORTED IN QUESliOH C-1; OTHERWISE ASK QUEStiON A S WORilEO. Was a household vehfcle used for tbis trip? I YES 2 NO > GO TO QUESTION 16 15. ENTER VEHICLE NUMBER 'I' WITH OUT ASKING IF ONLY ONE VEHICLE REPORTED EARLIER. OTHERWISE ASK QUESTION AS WORDED. vehicle? ____ VEHICLE HUHBER

PAGE 126

Appendix A. (Continued) section g (continued) 16. IF RESPONDENT WAS ALOftE IH THE VEHICLE, ENTER "1" AND ROSTER HUMBER WITHOUT ASKING QUESTIONS IS AND 16. Vho drove the longts t dfstanct on this trip, a household Member or s0111eone else? I HOUSEHOLD HEM8ER 2 HOT A HOUSEHOLD MEHBER > GO TO QUESTION 18 17. Who was that? ENTER ROSTER HIJHBER' --18. Now r have a few questfons about the return trfp from (OESTlNATlON). was ceans of tra nsportation used for the trip home? 114 [PROS: means of transportation was used for the longest distance ) 01 AUTO (INCLUDE STATION WAGON) 02 PASSENGER VAN OJ CARGO YAH 04 PICKUP TRUCK (INCLUDE PICKUP WITH CAHPER) OS OTHER TRUCK 06 RY O R MOTOR HOHE 07 MOTORCYCLE 08 MOPED/MOTORIZED BICYCLE 09 OTHtR P.O.Y. (SPECIFY) t9. W ere any people with you on this trip? I YES > GO TO Q.20 Z HO > GO TO Q.24 12 sus 13 AMTRAK 14 COMMUTER TRAIN 15 STREETCAR/TROLLEY 16 ELEVATED RAIL/SUBWAY 17 AIRPLANE 18 TAXI (COMMERCIAL USE) 19 BICYCLE 20 WALK 21 SCHOOL BUS 22 OTHER (SPECIFY) 20. ASK ONLY IF 2 O R MORE PERSONS LISTED ON HOUSEHOLD ROSTER: Vere any household with (you/PERSON) on the trip home? I YES Z HO > GO TO QUESTION 22 21. Which household members! [PROBE: Any other household .. obers7) ENTER ROSTER HUHBER(S): ----------

PAGE 127

Appendix A. (Continued) section g (continued) 22. Were any non-household members with (you/PERSON) on this trip? 1 YES 2 NO > GO TO VERIFICATION 23. How many non-household went on thfs trip with (you/PERSON)? NUMBER: ---YERIFICATION: So there (was one person/were persons) on this trip? VERIFY THAT THE SUK OF ENTRIES IN ITEMS 21 AHOiZ! PLUS THE RESPONDENT IS THE TOTAL NUMBER OF PERSONS IN THE PARTY. 115 Z4. How many miles did (you/PERSON) travel on the trip homt, including ones on side trips along th e way? ___ HILES CHECK ITEM: I S ONE OF CODES 01 09 ENTERED IN QUESTION 18? I YES > CONTINUE 2 NO > GO TO NEXT TRIP OR NEXt SECTION 25. HARK "NO" W ITHOUT ASKING IF NO VEHICLES REPORTED IN QUESTION Cl; OTY.;RWISE ASK QUESTION AS WORDED. a household vehicle u sed for this trip? I YES 2 HO > GO TO QUESTION 27 26. ENTER VEHICLE HUMBER "1" WITHOUT ASKING IF ONLY OHE VEHICLE REPORTED EARLIER. OTHERWISE ASK QUESTION AS WORDED. Which 'tthitle! ____ VEHICLE NUIISER 27. IF RESPONDENT HAS ALONE IN THE VEHICLE, ENTER "I" AND ROSTER NUII8ER WITHOUT ASKING QUESTIONS 27 AND 28. Who drove the longest distance on this trip, i household member or soceone else? I HOUSEHOLD MEMBER 2 HOT A HOUSEHOLD MEMBER > GO TO NEXT TRIP OR NEXT SECTION

PAGE 128

Appendix A. {Continued) 9 (conttnutd) 28. was that? ENTER ROSTER IIUHBER: -GO TO HOO TRIP OR NEXT SECTJOH. 116

PAGE 129

Appendix A. (Continued) 117 SECTION H TRAVEL DAY (HOUSEHOLD MEMBERS 14 YEARS OR OLDER: PROXY PERMITTED UIIOE R PROXY RULES. PROXY REQUIRED FOR PERSONS 5-13 YEARS) Row I have some q u estions about all trips (you/PERSON) took TRAVEL DAY). (inc luding long trips that .. y have already been reported). for these questions, a trip is: any time (you/PERSON) went from one address to another by car. bus, walking, b i cycling or SDDt other means. For example, if you leave work, stop at the store, and then continue boDe that would be two trips --one to the store and one froa the store to home. To be sure w e get all the trtps (you/PERSON) took during the day, we'll start at 4 a.m. in the morning and end at 3:59a.m. the next morning. First we'll list the trips including very short trips. O.K? IF QUESTION E OR .QUESTION E IS "YES', SAY: In telling._ about trips, 22 not i nclude trips made as an essential part of your work. --1. Oid (you/PERSON) qo anywhere (yesterday/on TRAVEL DAY)? 1 YES 2 NO > GO TO NEXT SECTION ((xcluding the trips taken as a Tegular part of the job), please tell me (you/PRSON) went (yesterday/on TRAVEL DAY). Remember, we want to know any time (you/PERSOn) went one place to another for any purpost. 2. d i d (you/PERSON) go first (yesterday/on TRAVEL DAY)? 1 HOME 2 OTHER (SPECIFY) J. (you/PERSON) left (DESTINATION) wflere did (you/PERSON) go next? 1 HOME 2 OTHER (SPECIFY) ---------------97 NO HORE TRIPS REPEAT QUESTION 3 UIITll NO HORE TRIPS.

PAGE 130

Appendix A (Continued) 118 h (continu ed) 4. On any of these tri@S d i d you use public trans portation for all or any part of the tr1p1 [PR08E1 Public tran sportation includes bus, tra in, streetcar, subway, and rail.} I YES > A S K H14 FOR EACH TRIP 2 HO > SKIP Hl4 FOR EACH TRIP UP TO 12 TRIPS CAN BE liSTED. IF MORE THAN 12 ARE REPORTE D USE TRAVEl DAY CONTINUATION FORKS. WHEN All TRIPS KAOE ON TRAVEl DAY HAVE BEEN liSTED, SAY: Wbllt I rtld tht trips I have listed, pl east think bact to (yesterday/TRAVEt DAY) to see tf th ere wtrt any trips you a f ght h1ve forgott e n to eent ion. READ liST: ADD AOOITIOHAL T RIPS IF REPORTED. WHEN All TRIPS HAVE BEEN liSTED AND VERIFIED, CONTINUE. CHECK ITEM 1: IS NCY OAT IN SECTION G, OUESTION 5 SN4 AS TRAVELOAY1 I YES > CONTINUE 2 HO > GO TO CHECK ITEM 2 of these trips wert p a rt of the longer trip to (DESTIMATIOH O F TRJP WITH OAlE AS TRAVEl OAY) thlt you told me about earlier? RE CONTINUE 2 NO > GO TO QUESTION 6 5. r:c-.,. 1 have I ftw quest(ons ibout tiCh trip. You told the pl1c e {you/PEASOH) wen t ws homt. Whit w11 m1in rtison (you were/PEASOK w1s) wy from home? 01 A T IIORK 02 IIORK RELATED 8USINESS 03 SHOP PING 0< OTHER FAHilY OR PERSONAl 8USIMESS OS SCHOOl/CHURCH 06 DOCIOR/OEHTIST GO TO QUESTION 8 07 VACATION 08 VISIT F RIENDS OR RELATIVES 09 PlEASURE DRIVIItG 10 OTHER SOCIAL OR RECREATIONAL II OTHER (SPECIFY) 6. Old the trip to (FIRST DESTINATION) begin ot hooo? I YES 2 NO

PAGE 131

Appendix A (Continued) sectfon h {continued) 1. What was the a&fn purpose of the trip to (OESTIHATJOH)? IF "RETURN" GTVER AS REASON, ASK FOR AHD CODE REASON fOR TRIP. 01 TO OR FROM WORK 02 WQRK RELATED BUSINESS 03 SHOPPING 04 OTHER fAMILY OR PERSONAL BUSINESS OS SCHOOL/CHURCH 06 DOCTOR/DENTIST 07 VACATION 08 VISIT FRIENDS OR RELATIVES 09 PLEASURE DRIVING 10 OTHER SOCIAL OR RECREATIONAL 11 OTHER (SPECIFY) 8. Were any other people wfth you on thfs trip? I YES Z NO > GO TO HIJ 9. ASK ONLY I f 2 OR MORt PERSONS liSTED ON HOUSEHOLD ROSTER: any househol d mecbers with {you/PERSON) on this trip? I YES 2 NO > GO TO QUESTION II 10. Which household members? [PROB Any other ENTER ROSTER NUMBER(S): ---------11. Old any nonhouseho. ld members go with (you/PERSON) on this trip? 1 YES 2 NO --> GO TO VERifiCATION 12. How many non-household members went on th's trip with {you/PERSON)? NUMBER: -----119 VERifiCATION: So there (was one person/were persons) on thfs trip? VERifY THAT THE SUM Of ENTRIES IN ITEMS 10 PLUS THE RESPONDENT IS THE TOTAL NUMSER OF PERSONS ON THE TRIP. 13. How far is it from where (you/PERSON) started to (DESTINATION)? ___ HILES 99997 LESS THAN ONEHALF MILE

PAGE 132

Appendix A. (Continued) section h (continued} 14. Did (you/PERSON) 'hange vehicles or eeans of transportation, or mbkt a transfer along the way? I YES > GO TO QUESTION 21 2 HO NOTE: QUESTIONS IS-20 ARE FOR NOHSEGHENTED TRIPS. IS. ASK ONLY IF HOT KHOWN: How did (you{PERSDN) get to (DESTINATION )? That is, what eans of transportation did (you/PERSON) ust for this trip? [ I F MORE THAN ONE MODE, CODE THE ONE USED FOR LONGEST DISTANCE.] 01 AUTO (INCLUDE STATION WAGON) 02 PASSENGER YAH 03 CARGO YAH D4 PICKUP TRUCK (INCLUDE PICKUP WITH CAMPER) OS O THER TRUCK 06 RV OR MOTOR HOME 09 MOTORCYCL E 10 HOPED{MOTORIZEO BICYCLE II OTHER P.O.V. (SPECIFY) 12 BUS 13 AMTRAK 14 COMMUTER TRAIN IS STREETCARITROLLEY 16 ELEVATED RAIL{SUBWAY 17 AIRPLANE 18 TAXI (COMHERCIAL USE) 19 BICYCLE 20 WALK 21 SCHOOL BUS 22 OTHER (SPECIFY} 16. t ime did (youfPERSON} begin the trip to (DESTINATION}? FORMAT: 07:SO A.M. 17. how many ainutes did it take to get there? ___ HIIIUTES CHECK ITEH 3: IS CODE 12, 14, IS OR 16 ENTERED IN QUESTION IS? I YES > CONTINUE NO > GO TO CHECK ITEM 7 18. How many oinutes did (you/PERSON) have to watt for the (TRANSPORTATION HI flUTES 120 19. Did (you{PERSON) sft, did (you{PERSON) stand, or did (you{PERSON) do both o n the (TRANSPORTATION HEANS}l I SIT ONLY >GO TO CHECK ITEM 7 2 STAIIO ONLY --> GO TO CHEn ITEM 7 3 SOME OF BOTH

PAGE 133

Appendix A. (Continued) section h (continued) 20. Which did (you/PERSON} do most of the tfme, sit or stlnd? I SIT 2 STAHD GO TO CHECK ITEH 7. NOTE: QUESTIONS 21 ARE FOR HULTISEGHENT TRIPS. 21. ASK ONLY If NOT KNOWN: What Deans of transportation did (you/PERSON) use f or the (first/next) part of this trip to (OESTIKATION)? 97 = NO OTHER PORTION OF > GO TO CHECK ITEM 7 01 AUTO (INCLUDE STATION WAGON) 02 PASSENGER VAN 03 CkRGO YAH o PICKUP TRUCK (INCLUDE PICKUP WITH CAKPER) OS OTHER TRUCK 06 RV OR HOTOR HOHE 09 MOTORCYCL E 10 MOPED/MOTORIZED BICYCLE II OTHER P.O.V. (SPECIFY) 12 BUS 13 AMTRAK 14 COMMUTER TRAIN 15 STREETCAR/TROLLEY 16 ELEVATED RAIL/SUBWAY 17 AIRPLANE 18 TAXI (COMMERCIAL USE) 19 BICYCLE 20 WALK 21 SCHOOL SUS 22 OTHER (SPECIFY) zz. ha t t ime d i d (you/PERSON) btgln this part of the trip? 07:SO A.H. 23. About how many minutes d id thfs part of the trip take? ________ MINUTES CHECK ITEM 5: IS CODE 12, 14, 15 OR 16 ENTERED IN QUESTION 21? I YES > CONTINUE NO > GO TO CHECK ITEM 6 24. How any minutei did (you/PERSON) have to walt for the (TRANSPORTATION HEJ;NS) l J!INUTES 121

PAGE 134


PAGE 135

Appendix A (Continued) section h (cont;nued) 30. Who wl> that? (I F HORE THAN ONE MENTIONED, PROBE: Which one drove the longest distance?] ENTER ROSTER NUMBER; ------123 31. Did (you/PERSON/the driv er) pay for parking during any part of this trip? I YES Z NO GO TO QUESTION 7 FOR NEXT lRIP{QUESTION 321NEXT SECTION QUESTION 32 IS A RANDOMLY SELECTED fRIP BY P.O.V. 32. Now r have one oore question about the trip to (OESTlHATlOH) that you said was o fJes and started at (ORIGIN). For that trip, please of m iles spent on any 2lane road, street, or an vndivfded highway with 4 or aore lanes; a d iv ided highway with 4 or more l a nes; or i n terstate highway, freeway, expressway, or other access highway. a. First. many miles were spent on a 2lane road, street, or highway {include any 3lane roads, streets, or __ HILES b. ln undivided highway with 4 or mort lanes? -IIILES c. highway with 4 or more lanes? __ HILES d. an interstate highway, fretway, expressway, or other -HILES CHECX I TEM: Does the sum of the miles g iven equal the number of ailes driven on thi> trip (+/! mile)l YES > GO TO NEXT SECTION NO > CONTINUE INTERVIEWER: THE SUH OF THE HILES DRIVEN ON EACH TYPE OF ROAD DOES NOT EQUAL THE NUMBER OF HILES DRIVEN OK THIS TRIP? 00 YOU WANT TO CORRECT THIS? I YES > GO TO QK32 2 NO > GO TO NEXT SECTION

PAGE 136

Appendix A. (Continued) 124 ow I d l ik e to ask a bout traffic accidents involving a vehicle on a public highway or road r e s ulting in property or persona l injury. Wt do not want to k now about acddtnts in p&rking lot. in 1 driveway. on a prh1t.e road, or i n a foreign country. l. (Have you/has PERSON) e ver been Involved in such an accident as the driver af 1 vehicle? 1 YES 2 KO > GO TO CHECK IT(M 2 2A. In what year d$d tht .OJt rec ent acctdtnt occur? [EHlER YEAR RAHGE: 01] [POSSIBLE SKIP] CHECX JTtH: Is OZA response last 5 y earsl YES > COMTIHU( NO >CO TO CHECK ITEM 2. 28. !n .onth did that ac.cfdtnt occur? [ENTER HOUTH RANGE: 1] CHECK J TEM 18: Is year and eonth wfthfn list 5 years? YES > CONTINUE NO > GO TO CHECK ITEH 2 3. How J havt 1 few que stions about thfs ac,fdent. In which state did t h e accident h appenr STATE: ---------4. Was written poltc t r t port pr epared? I YES 2 110 5. any pedestrian s fnvolvtd! I YES 2 HO [PAOBE: P e destrians a re p e ople not in vehicles, such as those walkfn;. ]

PAGE 137

Appendix A. (Continued) s ection f (continued) What type of vehicle you/was PERSON} in7 I AUTOMOBILE 2 PICKUP TRUCK 3 c VAN 4 OTHER T RUCK 1. Where a n y other vehicles involved? I YES 2 NO > GO TO QUESTION g 5 MOTORCYCLE 6 OTHER VEHICLE 9. 'What other types were involve d ? : (PROBE: Any other type?] E NTER All THAT A P PLY. I AUTOMOBIL E 2 PICKUP TRUCK 3 VAH 4 OTHER TRUCX 5 MOTORCYCLE 6 BICYCLE 7 O THER/U HKHO"N VEHICLE 9. Ofd the accident result in an injury t o anyone or 1n a fatality? I YES 2 HO > GO T O Q UESTION II 10. I'd like to know the most serious injury that resulted from the accide nt? Was it .. 125 1 an injury, but not serious enough for anyone to b e trans ported from the scene for medica l care. 2 x a n injury serious enough for someone to b e transported from the scene for medical care or 3 a fat a l inju ry? 11. D id the accident happen i n a city or town or did it happen in the open country? I CIT Y OR 2 OPEN COUNTRY 12. Did the a ccident happen on a n interstate highway. freeway, or expressway? I YES 2 HO > G O TO QUESTION 14

PAGE 138

Appendix A. (Continued) section i {cont inued} 13. Did t h e accident happen at an i nterchange; that is, at an exit or e ntra nce on t h e h;ghway? I YES 2 NO } -> GO TO QUEST I O N IS 14. Did the accident happen at an 1nters tctfon7 1 YES 2 NO IS. Was it during the daytime or it dark enoug h so thet headlights were n teded? I OAYTIHE 2 DARK 15. wou ld you best describ e the road condit i o n ? Was it .. 1 dry. z wtt. 3 snowy, or 4 icy? CoEC K ITEM 2 : IS THI S A NOHFAKILY HEHBER INTERVIEW? 1 YES > GO T O SECTION l 2 NO > GO TO S E C TIOK H 1 26

PAGE 139


PAGE 140


PAGE 141

Appendix A. (Continued) 129 In order to classify your household for statistical purposes, 1 need the total combined income for the rst 12 .onths; that 1s, th total income of ( REFERENCE PE ON) and (his/her family Include income from all sources such as wages and salaries, income from business or farm, Social Security, pensions dividends, interest, rent, and any other income receiv&d by members of this family. THE FOLLOWING IS DISPLAYED IF HOUSEHOLD HAS HDHFAHILY MEMBERS NOTE: THE HOUSEHOL D HAS NOH-FAMILY HEHBERS .. DO HOT INCLUDE THEIR IHCOfiE WITH FAMILY INCOME. 1. In the past 12 months, was your total combined family income from all sources ... I less than 140,000 or > GO TO QUESTION 2a 2 $40,000 or more? > GO TO QUESTION 4a 8 DON'T KNOW 9 REFUSED } > GO 10 CHECK ITEM 2a. it less t han S20,000? I YES > ASK QUESTION 2b 2 NO > GO T O QUESTION Ja 8 DOW T KHOil 9 REFUSED } > GO TO CHECK ITEM 2b. Was it less than $10,000? I YES > ASK QUESTION 2c 2 HO > GO TO QUESTION 8 DON'T KNOW 9 RErUSEO 2c. Was it ltss than SS1000? } > GO TO CHECK ITEM I YES } > GO TO CHECK ITEM 2 NO 2d. Was it less than SIS,OOO? 1 YES 2 NO } > GO TO CHECK IT[M

PAGE 142

Appendix A. (Continued) 3a. Was it ltss than SJ0,0007 I YES > ASK QUESTION lb 2 NO > GO TO QUESTION lc 8 DON'T kHOW 9 REfUSED ) > GO TO CHECK ITEM lb. Was it less than 125,0007 I Y 2 HO } > GO TO CHECK ITEM 3c. it less than S3S.ooor I YES 2 NO } > GO TO CHECK !TEM 4a. i t less tban $60,0007 I YES > ASK OU!STIOH 4b 2 HO > GO TO QUESTION 5 8 OOH' T kHOW 9 REfUSED } > GO 10 CHECK ITEH 4b. it l ess than 550,0007 I YES > ASK QUESTION 4t 2 flO > GO TO QUESTION 4d s oou'T xo 9 REiUS :c. it Jess than S4S,OOO? } > GO TO CHECK ITEM I YES 2 HO } > GO 10 CHECK ITEM f d. Vas it 1ess than SSS,OOO? I YES } 2 NO > GO 10 CHECK ITEM Sa. it l tss than $70,0001 I YES > ASK QUESTION Sb 2 NO > GO TO QUESTION 5< 8 OON'T KNOW 9 REfUSED } > GO TO CHECK ITEH 130

PAGE 143

' Appendix A. (Continued) 131 Sb. Was it less than S6S,OOO? 1 YES 2 NO } > GO TO CHECX !TEll Sc. Was it less than $75,000? I YES > GO TO CHECK ITEH 2 H0 > ASK QUESTION Sd 8 DON'T KNOW 9 REfUSED } > GO TO CHECK ITEM Sd. Hs it less thn $80,000? 1 s 't'ES 2 NO CHECK ITEM: } > GO TO CHECK ITEM IF NO hOUSEHOLD MEMSERS IN THE 5 T HROUGH 13 AGE GROUP, GO TO PERSONLEVEL INTERVIEW: CONTINUE. For the rest of the househol d members 14 and older will be asked' to answer questions for themselves; ha....ever, someone else will need to answer for younger h ousehol d members. Can you answer for them? 1 YES > GO T O SECTIOII E 2 ,. liO Who would be the best person to give the infor=ation about them? EIITER ROSTER HUMBE R : C OIITIIIUE WITH PERSON-LEVEL INTERVIEW.

PAGE 144

Appendix A (Continued) 132 SECTION L INCOME Of NOH-FAMILY MEMBERS (NON-fAMilY ADULT HOUSEKOLO KEKBERS) In order to classify this housing unit for statistical purposes, we need your total co.bined income. Total income includes income fro. all sources suc h as wages and salaries, income f rom business or fana, Socia l Security, pensions, dlvid ends, interest, rent, and any other income received. 1. In the past 12 .anths, your total incORe all sources less than .. a $10,0001 ... 01 ... 02 b. S20,0001 ........... 01 ...... 02 c. $30,000? ........... 01. ......... 02 d. S40,000? ........ .01 . ........ 02 $50 000? ........... 01 ... ..... 02 t. s6o.ooo1 ........... o1 .......... oz 9 s7o.ooor . ......... ot .......... oz h. S80,0001 .......... 01 ..... ... 02 r FIRST 'YES" CAT I WILL SKIP TO QUESTION Z. IF 'OOK'T KNOW" OR REFUSED," e
PAGE 145


PAGE 146

134 APPENDIX B: TABULATIONS Tabulations Nume rous cross-tabulations were completed on the 1990 NPTS data using the SAS procedures described in Chapter 3. The following section lists selected cross tabs for each data file by unit of measure and the stratification variables. Household File 1. Households by household income 2. Households by number of autosjvans in household. 3. Households by number of trucks in household. 4. Households by number of vehicles (HHVEHCNT) in household. 5. Househo lds by household MSA. 6. Households by urban area size. 7. Households by household size. 8 Households by number of workers in household 9. Households by hou sehold size, number of vehicles, and number of workers in household. 10. Households by household size, number of vehicles, and number of drivers in household. 11. Households by number of workers, number of vehicles, and number of drivers in household. 12. Households by household income and number of vehicles in house hold 13. Households by availability of and distance to public transit. Person File 1. Persons by age and gender. 2. Persons by race and gender. 3. Persons by hispanic origin and gender. 4. Persons by household income and household size. 5. Persons by usual mode of transportation to work. 6. Persons by age, gender, licensed driver, and worker. 7. Persons by licensed driver, worker, household income, and urban area size. a. Persons by parking code and parking costs. 9 Ucensed drivers by age and gender. 10. Average household size by household income and urban area size.

PAGE 147

Appendix B. (Continued) Vehicle Rle 135 1 H ousehold vehi cles by urban area size and annualized vehicle mileage. 2. Household vehicles by vehicle type and annualized vehi c le mileage. 3 Ave rag e annualized vehicle mileage by household size and household income. 4. Average annuali zed vehicl e mileag e by vehicle type and vehicle age. 5. Average annualized vehicle mileage by veh i cle type and urban area size. 6. A verage annuafiZed vehicle mileage by vehicle type and household income. Trave l Day File 1. V ehic l e trips and miles by age, gender, and purpose 2 Vehic l e trips and miles by age, gender, and mode 3. Vehicle trips and miles by purpose and dlstance. 4 Vehicl e trips and miles by purpose and mode. 5 Vehicle trip s and miles by purpose and income. 6. Vehicle trips and miles by purpose and number of occupan ts. 7. Vehicle trip s and miles by purpose and number of vehicles in household. 8. Ve hicl e t rips and miles by purpose and urban area size. 9. V ehicle tr ips and miles by purpose and day of week. 10. Veh icl e trips and miles by purpose and trip start time. 11. V e hicle trips and miles by household Income and urban area size 12. Vehicle tr ips and miles by household income and number of vehicles in household. 13. Vehicle trips and miles by househo ld size and number of veh icles in household. 1 4 Vehicle trips and miles by t rip duration. 15. Vehicle tr ips and miles by trip duration and n umber of occupants for home-to-work trips 16. Vehk:le trips and miles by mode and distan ce 17. Veh icl e trips and miles by mode and urban area size. 18 Pe rson trips and miles by age, gender, and purpose. 19. P e r son trips and miles by age, gender, and mode. 20 Person trips and miles by purpose and d i stance 21. Person trips and miles by purpose and mode. 22. Person trips and miles by purpose and income. 23 Person trips and miles by purpose and number of vehicles in household. 24. Person trips and miles by purpose and urban area size. 25. Person trips and miles by purpose and MSA size 26. Person trips and miles by purpose and household location. 27. Pers on trips and miles by household income and urban area size.

PAGE 148

Appendix B. (Continued) 136 28. Person trips and miles by household income and number of vehicles in household. 29. Person trips and miles by household size and number of vehicles in household. 30. Person trips and miles by trip duration. 31. Person trips and miles by trip duration and number of occupants for home-to-work trips. 32. Person trips and miles by mode and distance. 33. Person trips and miles by mode and urban area size. 34. Travel time by purpose and mode Travel Period File 1. Vehicle trips and miles by age, gender, and purpose. 2. Vehicle trips and miles by age, gender, and mode. 3. Vehicle trips and miles by purpose and distance. 4. Vehicle trips and miles by purpose and mode. 5. Vehicle trips and miles by purpose and income. 6. Vehicle trips and miles by purpose and number of occupants. 7. Person trips and miles by age, gender, and purpose. 8. Person trips and miles by age, gender, and mode. 9 Person trips and miles by purpose and distance. 10. Person trips and miles by purpose and mode. 11. Person trips and miles by purpose and income. 12. Person trips and miles by purpose and number of occupants. Segmented Travel Day File 1 segment wait time by purpose and mode. 2. segment travel time by purpose and mode.

PAGE 149

137 APPENDIX C: GLOSSARY This glossary In cludes tenns common to the 1990 NPTS survey. The fol l owing definitions were provided by FHWA i n several of their publk:ations related to this study. Driver A person who operates a motori:ted vehicle. If more than one person drives on a single trip, the person who drives the most miles i s classified as the princ i pal drive r Employed A person is considered empl oyed if there i s a definite arrangemen t for regular full-time ar part-time work for pay every week or e very month A formal definite arrangement with one or more employe r s to work a specified number of hours per week or days per month but on an irregular schedu l e during the work month is also con sidered employed. A person who is on cal l to work whenever there is a need for his/her services is no t considered employ ed. Househo l d A group of persons wh ose usua l plaoe of residence is a specific hous i ng unit; these pe r sons may or m a y not be relate d to each other. The total of all U.S. households represents the total civilian non-institutionali:ted population. Does not include g roup quarters (i.e., 10 or more persons living t ogether none of whom ere related) Household Income The money i ncome of all family members in a h ousehold inclu ding those temporarily absent. Annual i ncome is asked lor the 12 months preceding the interv i e w I nclud es income from a ll souroes, such as wages and salary, commiss i ons, tips, cash bonuses, income from a business or farm, pensions, dividends, interest, unemploym ent or workmen's compensation, social security, v eterans' paymen ts, rent rec eived from owned property (minus the operating costs), public assist an ce payments regular gifts of money from friends or relatives not living In the household, alimony, child support, and other kinds of periodic money income othe r than earnings Excludes In-kind Income such as room and board insurance payments l ump-sum I nheritances, occasional gifts of money from persons not living in the same household, withdrawal of savings from banks, tax r efu nds, and the proceeds of the safe of one's house, car, or other personal property. Household Me mbers All peop le, whether present or tempo rarily absent, whose usual place of resi dence is in the sample unit. I nclu des people sta ying in the samp le unit who have no other place of residence elsewhere

PAGE 150

Appendix C (Continued) 138 Household Trip One or more household members traveling together. Household Vehicle A motorized vehicle that is owned leased rented or company-owned and available to be used regularly by household members during the travel period Includes vehic l es used solely for business purposes or business owned vehicles if kept at home and used for the home to work trip, (e.g., taxicabs, po l ice cars, etc.) which may be owned by, or ass igned to, household membe r s for their r egular use. I ncludes all vehicles that were owned o r available for use by members of the household d u ring the trave l period even though a vehicle may have been sold before the interview Excludes vehicles that were not working and not expected to be working within 60 days, and veh i cles that were purchased or received after the designated travel day Jou rn ey to-Worts Includes travel to or from a place where one reports for work Does not include any other work related travel. Lice n sed O d ver Any person who holqs a valid driver s license from any state. Means of Transportation A mode used for going from one place (odgin) to another (destination). Includes private and public modes, as well as walking For all travel day trips, each change of mode constitutes a separate trip The following transportation modes, grouped by ma jor mode, are included : Private Veh i cle Auto mobi le A privately owned and 1 or oper ated licensed moto d zed vehicle inc l ud i ng cars j eeps and station wagons. Also includes leased and rented cars if they are privately operated and not picking up passengers in return for f are. llallPrivate l y owned and/or operated vans and minivans designed to carry from 5 to 13 passengers or to haul cargo Pickup !ruck -A motorized veh i cle pdvately owned and/or operated with an enclosed cab that usually accommodates 2-3 passengers and an open cargo area in the rear. P i ckup trucks usually have about the some wheelbase as a full-size station wagon. Other Truck A ll trucks other than p i ckups, i .e., dump trucks, trailer trucks, etc. RV /Motorhome Includes self powered recreationa l vehicles that are operated as a un i t without being towed by another veh i cle (e.g. a Winnebago motor home). Includes l arge medium and small motor cycles. Does not i nclude minibikes wh ich cannot be licensed for highway use. Public Transportation .aw;-Includes intercity buses, mass transit systems, and shuttle buses that are available to the general public. Also includes Dial-A-Bus and Senior Citizen buses that are availab l e to the publ i c Does !lQ1 include

PAGE 151

. . Appendix C (Continued ) 139 shuttle buses OP.erated by a government agency or private industry tor the convenience of employees, contracted or chartered buses or school buses. Commuter Train Includes commuter trains and passenger trains other than elevated trains and subways. In cludes local and commuter train service. Does not include Intercity service by Amtrak. Streetcarffiolley Includes trol l eys, streetcars, and cable cars. El e vated Ra il/SubwayIncludes elevated and subway trains in a city. Other Modes A i rplane includes commercial airplanes and sma ll er planes that available for use by the general public In exchange for a fare. Private planes and helicopters are included under "other." The use of a taxicab by a driver for hire or by a passenger for fare. Also includes alrport limous i nes. Does not Include rental cars if they are privately operated and not picking up passengers I n return for tare. B i cycl e I ncl udes bicy cle s of all speeds and sizes that do not have a m otor. Amt r ak The U.S na tio nal passenger railroad service provid i ng I nter c ity tra i n service. W al k Includes jogging, walk i ng, etc ., provided the origin and destination are not the same. School bus Includes county school buses, p rivate school buses, and buses chartered from private companies for the express purposes of carrying students to or from school and/or school-related activities. Moped Includes motorized b icycles equ ipped witl1 a small eng i ne, typ i cally 2 h orsepower or l ess. Also i ncludes minibikes s uch as dirt bi k es an d traD bikes. Not e tha t a m otorized b i cycle mav o r m ay not be li censed for h i ghway u se Ot h e r Includes any types of transportation not listed above Metropolita n Statistical Area (MSA) Except in the New England States, a MSA Is a county or group of contiguous counties wh ich contains at least one c ity of 50,000 inhabitants or more, or "tw in with a combined population of at least 59,000. In addition contiguous counties are included in an MSA If, according to certain they are social l y and econom i cally Integrated with the central In the New England States, MSA s consist o f towns and cities instead of counties. OccypancyThe number of person includ i ng driver and passenger(s ) I n a veh i cle. NPTS occupancy rates are generally ca l culated as person miles divided by veh i cle miles. PassengerFor a specific trip, any occupant of a motorized vehicle, other than the driver.

PAGE 152

Appendix C (Continued) 140 ee r son Miles of Travel A measure of person travel When one person travels one mile one person mi l e of travel resu l ts. Where 2 or more persons travel t ogether i n the same vehicle each person makes the same number of p erson miles as the vehicle miles. Therefore, fou r persons travel i ng 5 miles in the same vehicle, make 4 times 5 or 20 person m il es. Person Trip A person trip is a trip by one or more persons in any mode of transportation. Each person is considered as making one person trip. For example, for persons traveling together in one auto make four person trips. Travel Day A 24-hour period from 4 : 00 a.m. to 3:59 a.m. designated as the reference period for studying trips and trave l by members of a sample household Iravel Perjod The 13 days immed i ately preceding the travel day and the des i gnated travel day for a sampled househo l d, for a tota l of 14 days. Trip Puroose The main reason that motivated the trip. For purposes of th i s survey, there are 11 reasons. For travel day trips, if there was more than one reason, and the reasons do not involve different destinations, then only the main reason is chosen. If there are two or more reasons, and they each involve different destinations, then each reason is classified as a separate trip. For travel period trips, if there was more than one reason the pr i mary reaso n was coll ected. Urban i zed Area An approx i mate classifica tion of sample househo lds as belong to an urbanized area or not. Those classified as belonging to an urbanized area were eithe r (a) in a central city of an MSA, or ( b) in a MSA but outside the central city, and with i n a z i p code area with a population dens ity of at l east 500 people per square mile in 1990. VehicleI n the 1969 survey, vehicle r efers to autos and passenger vans owned or available to the household. I n the 1977, 1983, and 1990 surveys, the term vehicle was expanded to include pickups and other l ight trucks RV's, motorcycles and mopeds owned or available to the household. Estimates show that in 1969 there were an additional 7.5 m i llion pickups and other l ight trucks that are not reflected in the 1969 NPTS data. vehicl e Miles of Trayel A unit to measure vehicle travel made by a private vehic le, such as an automob i le, van, pickup truck or motorcycle Each mile trave l ed is counted as one vehicle mile regardless of the number of persons in the veh i cle. Vehicle Trip A trip by a single veh i cle r egardless of the number of persons in the vehicle. Worker See "Employed."