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Evaluation of Contraflow Lanes for Hurricane Evacuation by Jason Collins, Ph.D., P.E., AICP A dissertation submitted in partial fulfillment of the requirement s for the degree of Doctor of Philosophy in Civil Engineering Department of Civil and En vironmental Engineering College of Engineering University of South Florida Major Professor: Jian Lu, Ph.D., P.E. William Carpenter, Ph.D., P.E. Robin Ersing, Ph.D. Manjriker Gunaratne, Ph.D., P.E. Edward Mierzejewski, Ph.D., P.E. Steven Polzin, Ph.D. Date of Approval: May 3, 2008 Keywords: freeway management, em ergency planning, reverse laning Copyright 2008, Jason Collins
NOTE TO READER The original of this document contains color t hat is necessary for understanding the data. The original dissertation is on file with the USF library in Tampa, Florida.
ACKNOWLEDGEMENTS There are numerous persons I wish to acknowle dge who aided me in th e completion of this research. The researcher would like to thank eac h member of the dissert ation committee. Their perseverance in helping to ensure a quality dissertation is appreciated. The committee consisted of the following: Jian Lu, Ph.D., P.E. Major Professor William Carpenter, Ph.D., P.E. Robin Ersing, Ph.D. Manjriker Gunaratne, Ph.D., P.E. Edward Mierzejewski, Ph.D., P.E. Steven Polzin, Ph.D. Also, thank you to my parents, Joseph and Kathleen Collins, and my two ol der sisters Kristin and Martha. Your influence has given me the desire to continue with the knowledge that almost any personal goal can be achieved. Al so, the researcher would like to thank Naved Siddiqui for his review and for his analysis formatting suggestions. Finally, this project would not hav e been possible without the support of my wife Carly, who became my wife during the time this research was undertaken. Her patienc e and understanding will always be remembered.
i TABLE OF CONTENTS LIST OF TABLES ................................................................................................................ ............. iii LIST OF FIGURES ............................................................................................................... ............. v ABSTRACT ...................................................................................................................... ............... vii INTRODUCT ION .................................................................................................................. ............. 1 Problem Defi nition ............................................................................................................ .... 2 Research Ob jective ............................................................................................................ .. 3 Dissertation Outline .......................................................................................................... .... 4 DEVELOPMENT OF HURRIC ANE PLANNI NG ................................................................................ 7 Databases and Res earch Centers ....................................................................................... 8 History of Hurricane Evacuation Studies ............................................................................ 13 Hurricane Evacuation Studies Between Different Regions ................................................. 16 Evacuation Demand and O perations Modeling .................................................................. 27 Summary of Evacuation Pr ocedures in Florida .................................................................. 36 RESEARCH METH ODOLOGY ....................................................................................................... 40 Development of Contrafl ow Alternat ives ........................................................................... 41 Development of Perf ormance M easures ............................................................................ 52 Evaluate Contrafl ow Logist ics ............................................................................................ 55 Perform Capacity and Trav el Time A nalyses ..................................................................... 57 Development of Sugges tions/Conc lusions ......................................................................... 60
ii DATA ASSU MPTION S .............................................................................................................. ...... 64 Sources of Data ............................................................................................................... .. 64 Driver Behavior and Ev acuee Assump tions ....................................................................... 65 Roadway Characterist ic Assump tions ................................................................................ 67 Traffic Volume Assumptions ............................................................................................... 72 RESULTS ....................................................................................................................... ................. 74 Improved C apacit y ............................................................................................................. 75 Required Infra structure....................................................................................................... 84 Required Pe rsonnel ........................................................................................................... 88 Speed Vari ation ............................................................................................................... ... 93 Logistics ..................................................................................................................... ........ 96 Delay/Conge stion ............................................................................................................. 103 SUMMARY/CONCL USIONS ......................................................................................................... 1 07 Observations and Uncertai nties ....................................................................................... 111 Alternative Method of Weight ing Performanc e Measures ................................................ 113 Future Re search .............................................................................................................. 117 REFERENC ES .................................................................................................................... .......... 120 APPENDICE S .................................................................................................................... ........... 123 Appendix A: LOS E Service Volume Simula tion Reports ................................................ 124 Appendix B: Total Throughput at Constant Speed Simu lation Reports ........................... 169 ABOUT THE AUTH OR ........................................................................................................ End P age
iii LIST OF TABLES Table 1 Speed C enter Exper tise .............................................................................................. ..... 11 Table 2 Louisiana State Univer sity Research Areas ..................................................................... 12 Table 3 Comparison of Authority St ructure for Hurric ane Evacuati ons ......................................... 17 Table 4 Planned Contraflow Evacuation Routes ........................................................................... 24 Table 5 Comparison of Evac uation Modeling Program s ............................................................... 34 Table 6 State Comparison of Contraflow St rategies ..................................................................... 45 Table 7 Matrix Format Summary ............................................................................................... .... 62 Table 8 Source s of Data ..................................................................................................... .......... 65 Table 9 Average Speed Comparison with Constant Volume ........................................................ 79 Table 10 Total Throughput Com parison by Alte rnative ................................................................. 81 Table 11 Simulation Modeling Result s for Analyzing Tota l Through put ........................................ 82 Table 12 Cumulative Evaluat ion of Improv ed Capacit y ................................................................. 83 Table 13 Improved Capacity Perf ormance Measur e Summary ..................................................... 84 Table 14 Equipment Cost Com parison ......................................................................................... 86 Table 15 Required Number of Orange Cones for Operati on ......................................................... 87 Table 16 Alternative Comparis on of Required Equipment ............................................................ 87 Table 17 Summary of Required Infr astructure Perform ance Meas ure .......................................... 88 Table 18 Summary of Required Pe rsonnel Perform ance Meas ure ............................................... 92 Table 19 Summary of Speed Vari ation Performanc e Measur e ..................................................... 95
iv Table 20 Summary of Logisti cs Performance Measure ............................................................... 103 Table 21 Average Delay Comparison wi th Constant Tota l Volume ............................................. 104 Table 22 Summary of Delay/Conges tion Performance Measure ................................................ 106 Table 23 Summary of Perform ance Measure Ev aluation ............................................................ 109 Table 24 Summary Matrix Using We ighted Scaling Al ternative .................................................. 116
v LIST OF FIGURES Figure 1 Florida Evacuation from Hurricane Charle y in 2004 .......................................................... 1 Figure 2 Schematic Comparison fo r Evacuation Res ponse Time ................................................... 2 Figure 3 Hurricane Katrin a Evacuation in 2005 ............................................................................... 7 Figure 4 Hurr icane Floyd .................................................................................................... ........... 21 Figure 5 Coastal Hurricane Evacuat ion Zones and Inland Storm Da mage ................................... 30 Figure 6 Typical Cross Section of Each Contraflow Strat egy ........................................................ 45 Figure 7 Bridge Span Safety C onsideration for Shoulder Lane ..................................................... 46 Figure 8 Florida Real Time Tr aveler Informat ion Webs ite ............................................................. 48 Figure 9 Florida DOT Traf fic Count Locat ion M ap ......................................................................... 49 Figure 10 Daily Traffi c Volume History ...................................................................................... .... 50 Figure 11 I-4 Crossover Locat ions for Cont raflow ......................................................................... 51 Figure 12 Components of Evacuation Time .................................................................................. 57 Figure 13 Study Area Locat ion ............................................................................................... ....... 59 Figure 14 Evacuat ion Network ................................................................................................ ...... 69 Figure 15 Directional Service Volume ........................................................................................ ... 70 Figure 16 Previous I-4 Contrafl ow Design Plans at SR 417 .......................................................... 72 Figure 17 Contraflow Average Speed Compar isons Using LOS E Se rvice Volu mes .................... 80 Figure 18 Total Saturation Flow vs. Contraflow Alternative for LOS E Service Vo lume ................ 80 Figure 19 Total Throughput vs. Contraflow Alte rnatives ............................................................... 83
vi Figure 20 Alternative D Personnel Requ irement s ......................................................................... 90 Figure 21 Average Speed Variation Between Regular Lanes and Cont raflow Lanes ................... 94 Figure 22 FDOT Contrafl ow Logistical Handout ............................................................................ 98 Figure 23 Conceptual Time Line of Ev ents to Implement Contraflow ............................................ 99 Figure 24 Summary of Set Up and Breakdown Time .................................................................. 102 Figure 25 Average Delay Comparison wi th Constant Tota l Volume ............................................ 105
vii EVALUATION OF CONTRAFLOW LA NES FOR HURRICANE EVACUATION Jason Collins, Ph.D., P.E., AICP ABSTRACT This dissertation evaluates contraflow during a hurricane evacuation for gr ade separated highways. Contraflow is the concept of reversing the typi cal direction of highway travel to provide more outbound roadway capacity. The Stat e of Florida has spent more time and resources towards the planning and the designing of potential contraflow facilities t han any other state in the country; however, contraflow has yet to be implemented (as of Summer 2008). This study determines if the additional capacity benefits of cont raflow outweigh the logistical requirements of implementing contraflow. Five different alternatives of c ontraflow lane configurations were comparatively evaluated. The format of this study is unique due to the evaluation of both capacity and logistical measurements. Each alternative was subject to evaluation of six different performance measures. The six different performance measures consisted of improved capacity, speed vari ation, logistics, required personnel, required infrastructure, and delay/cong estion. Each performance measure was evaluated using a scaled scoring system. The alte rnative with the lowest average scoring among the different performance measures wa s considered the best alternative.
viii Contraflow should only be consider ed as a last resort. The loss of inbound access, safety concerns, logistical requirements, and the additional stra in of public resources during an evacuation are negative aspects that should be consider ed when determining the capacity benefit. If extenuating circumstances justify contraflow, then a full conversion of all inbound lanes to outbound lanes, known as Alternative D, should be considered. This alternative demonstrated the greatest capacity benefit while requiring the least amount of public resources. However, instead of contraflow, it is suggested to divert public resour ces towards other, more practical alternatives. Real time traffic moni toring has been demonstrat ed to be quite useful. Publicly accessed web-pages on t he internet and the recent insta llation of variable message signs all provide improved notification of traffic conditions and of the c apability to use alternative atgrade evacuation routes in addition to using the grade s eparated highways. This driver notification and the ability to ensure the safe and efficient tra vel on these alternative routes may be worth further investment, as well as being a po tential topic of future research.
1 INTRODUCTION The event of an evacuation potentially contains the most demanding set of circumstances with regard to the transportation infrastructure. Mil lions of people from ur ban areas gather belongings and travel towards safety in a relatively short period of time, sometime s resulting in extreme congestion. The research topic of hurricane evacuation is continuous ly emerging, and new opportunities for improvement are identified after virtually each hurricane. Figure 1 Florida Evacuation from Hurricane Charley in 2004
2 Problem Definition As more vehicles crowd the roadw ays, the increase in density re sults in congestion and causes delay for the traveler, as represented in Figure 2. Roadways provide a finite amount of capacity. When the demand exceeds the availabl e capacity, the overflow dem and is held stationary, causing delay until the excess demand can be served. Note: All values of Evacuat ion Time are in generic units. Figure 2 Schematic Comparison for Evacuation Response Time One countermeasure in providing more efficiency of the available roadway capacity is the use of contraflow lanes, which redirects inbound travel l anes toward the outbound direct ion of evacuation; 0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100% Evacuation Time Evacuation Percenta g e
3 however, the use of contraflow has only been activa ted a few times in the United States and has not yet been activated on any grade separated highways in the State of Florida (as of 2007). The use of contraflow during an evacuation requires signific ant deployment of public resources during a time period when it is vital to have these resources available for other purposes. A problem arises if public resour ces are deployed to implement c ontraflow when the absolute need for contraflow may not ex ist. While contraflow provides im proved capacity, contraflow may not be an effective method of evacuation when one consid ers the number of security, law enforcement personnel, and resources that are required. T herefore, this dissertation study has been compiled for the purpose of addressing the nece ssity to implement contraflow in Florida. Additionally, the identification of which methods of contraflow are most effective is a question warranting analytical research. Research Objective The objective of this dissertation is to deter mine the necessity of contraflow for evacuation purposes. The focus is not only to improve capa city, but to also give consideration to the investment of public resources. If the determinat ion is made that contrafl ow benefits outweigh the disadvantages, then the objective bec omes determining which form of c ontraflow is most effective. The research begins with the evaluation of existing lo gistical procedures within the state of Florida, and then identifying improvements to the existing des ign plans and procedures. This dissertation is unique in that the Measures of Effectiveness (MOEs) are focused to evaluate both additional capacity benefits and logist ical requirements.
4 While the study is directed towards hurricane evac uation procedures in Florida, several aspects of this study may be applied within other regions of the United States and contribute toward the advancement of the civil engineer ing and emergency planning profe ssions. This dissertation may also be applied to other countries that experience mass evacuation of the general population. This research demonstrates that the use of contraflow lanes may not be needed to be the most effective evacuation plan on I-4 in Florida, but that other investments may be more effective when considering the access and logistical c onstraints associated with contraflow. Dissertation Outline This dissertation is a comprehensive examinati on of recommended evacuati on procedures and is a quantitative evaluation between the adv antages and disadvantages of contraflow. The result is the identification of suggested logistical methods toward enhancing the investment of public infrastructure and improved capacity. The examination begins with detaile d literature review of research dedicated to the advancement of evacuation planning and the compil ation of knowledge from previ ous hurricane evacuation studies. Evacuation studies between Florida and other stat es are then compared. Previous studies also include evacuation demand and operat ions modeling. A summary of evacuation procedures in Florida is then presented. The research methodology is then presented. The section begins with a description of each contraflow alternative. A descr iption of the performance measures is defined in this section.
5 Administrative and logistical procedures are t hen evaluated. Development of how suggestions and conclusions are defined is also pr ovided. The presentation of t he comparative matrix between the contraflow alternatives and the performance measures concludes the research methodology. Data sources are then presented defined, which are a foundation of the analysis. A description of how capacity and travel time analyses are performed is addressed. The data assumptions about driver behavior and evacuee tendencies address user characteristics. Data assumptions about roadways and traffic volumes address in frastructure characteristics. Results of the analyses are then presented. T he results of each performance measure between each contraflow alternative are provided in terms of: Improved Capacity Required Infrastructure Required Personnel Speed Variation Logistics Delay/Congestion The comparative matrix then summarizes the perf ormance measures in the Summary/Conclusions section of the dissertation. The determinat ion of whether contraflow benefits outweigh disadvantages is concluded, as well as which contraflow alternative would be considered most effective. The dissertation is completed with a discussion of future research that could be considered as a continuation of this research. A perspective of le ssons learned during this process is then provided.
6 The dissertation then concludes with a bibliography of references and also with appendices that provide documentation of analytical results.
7 DEVELOPMENT OF HUR RICANE PLANNING Improvements for hurricane preparation and evacuation are constantly being identified. Something new is learned after each hurricane; therefore, much established research has evolved over the past fifty years. Particularly, the emphasis of transportation planning has advanced and has become a fundamental part of effective hurricane ev acuation during the past 20 years. This section identifies some of the previous advancements that have been made in evacuation modeling and the implementation of contraflow lanes for evacuation. Figure 3 Hurricane Katrina Evacuation in 2005
8 This section begins with a summa ry of existing databases and resear ch centers that are established for research in hurricane planning. The topic of how hurricane evacuation studies have evolved for regional planning purposes is then addressed. A comparison of how hurri cane evacuation studies are conducted between Flor ida and other regions in the country is performed. This comparison utilizes governmental authority structures and differ ent adopted contraflow strategies. A review of how evacuation demand and traffic operations m odeling have become incorporated into hurricane evacuation studies is then undertaken. A summa ry of existing hurric ane evacuation procedures planned within the state of Florida then concludes the Literature Review. Databases and Research Centers Hurricane planning is a discipline t hat has significantly in creased in recent history. This growing field of research is now recognized by both Federal Highway Administration (FHWA) and FEMA and is now represented as a Transportation Research Board subcommittee (A3B01(4) Subcommittee on Emergency Evacuation) to help communicate new practices and data on this topic. Specifically, the subcommittee addresses the following topics: To research and develop faster more efficient, and more effective evacuation strategies Information exchange, Best-Practices documents, identify research needs Apply information for more routine conditi ons and for management of special event traffic Develop operational and safety guidelines fo r interstates and other major roadways during evacuations, including design standards for interstate and other major highways when operating them contra-flow for evacuations.
9 Applications of ITS and remote sensing system s for evacuations, including the collection, processing, and communication of roadway and weather data to decision makers, evacuees, business and commercial carriers. Incorporate evacuation travel demand forecasting and operational planning. Evaluate human behavior/human factors issues in evacuations. Determine traffic enforcement issues for evacuations. Research organizations have been developed to adv ance the field of hurricane planning. The International Hurricane Research Center (IHRC) at Florida International University (FIU) brought together the expertise of the public universitie s in Florida into an integrated multi-year, multidisciplinary cooperative research effort known as the Florida Hurricane Al liance. The Alliance is coordinated by the IHRC, drawing upon its mission as a center responsible for hurricane research, education and outreach. Individual Alliance member s take the lead for specific research projects, on the basis of capabilities and rele vant expertise, and working in par tnership with other Alliance members. The members on the alliance focus primarily on the following types of research: Cost of Hurricane Warnings FIU and Florida A&M University (FAMU) Weather Networks University of North Florida (UNF), FAMU Coastal Vulnerability & Forecasting FIU, Florida Atlantic University (FAU) Storm Surge FIU LIDAR FIU, University of Florida (UF) Simulation and Visualization FIU, Un iversity of Central Florida (UCF) Surface Wind UF, FIU Hurricane Structure and Prediction Florida State University Ecological Impacts University of South Florida
10 More recently, the Severe Storm Prediction, E ducation and Evacuation from Disaster Center, or SSPEED, was created. The cent er is an academic and public partnership. Inaugural members include seven Texas universities and the Loui siana State University Hurricane Center. The SSPEED Center, which is housed in Houston, Texas, and based at Rice University, organizes universities, researchers, emergency managers and private and public entities to better address severe storm impacts from Texas to Louisiana in a zo ne that includes major cities along the Gulf of Mexico. The SSPEED Center's research areas include: Severe storm and hurricane res earch and storm surge prediction Radar-based rainfall and flood warning systems for urban and coastal areas State-of-the-art educational programs for workforce training and public awareness Infrastructure risk assessment for s heltering and evacuation from disaster Evacuation plans linked to the best warni ng and transportation systems, and societal needs. The SSPEED Center's expertise is applied through the different universities as described below.
11 Table 1 Speed Center Expertise Research Center Research Focus Louisiana State University Storm surge model predi ction; evacuation and transportation planning Rice University Flood prediction and warn ing; urban hydrologic models; Web integration of real-time data; regional forecast test bed; public policy and response University of Houston Educational outreach for public and high schools; infrastructure risk assessment University of Texas-Austin Disaster planning; st orm surge modeling; remotely sensed data; evacuation and transportation systems Texas A&M and TAMU-Galveston Coastal flood evacuation; storm surge impacts; community response, land planning in the coastal zone Texas Southern University Transportation systems and evacuation planning University of Texas-Brownsville Coastal flood response; regional forecast test bed; international border issues Houston-Galveston Area Council Evacuation planning and transportation management; lead governmental unit for operations and response The Louisiana State University holds a hurricane research center that has special focus on transportation planning. The following list indica tes a number of the areas of hurricane and hurricane-related expertise and ongoing resear ch at the university. (Wilmont, 2001)
12 Table 2 Louisiana State University Research Areas Hurricane Frequency/ Intensity Hurricane climatology Paleotempestology Storm track prediction Effects of global climate change Modeling Storm surge flooding Wave modeling Riverine rainfall flooding Wind and wave fields Rain-induced landslides Evacuation traffic flow Wind effects on structures and wind tunnel modeling Coastal erosion/ land loss Coastal response/geology Impacts of coastal restoration Chemical releases in extreme weather Nuclear releases in extreme weather Hurricane Impacts Natural Environment: Coastal erosion/ wetland loss Barrier islands, estuarine environm ental modifications, geomorphology Fish kills/ marsh kills Effects on agriculture Effects on aquaculture Effects on forestry resources Built Environment: Effects on infrastructure (roads, bridges, utilities, hospitals, schools, etc.) Effects on petroleum/chemical industries, onshore and/or offshore Effects on building stock Strength and stability of levees Human Environment: Effects on social organization Use of social networks to cope with hurricane impacts Effects of preexisting social networks on formal and informal aid and patterns of provision of informal support Effects on depressive symptomatology Effects on work disruption Epidemiology of floods Economic Impacts Preparedness Use of GIS for planning/ response activities Risk assessment Rainfall flood/ storm surge mapping Hurricane refuge/ shelter selection Evacuation planning Technology and emergency management Assessment/ evaluation of emergency management systems. Response (RealTime data analysis for landfalling hurricanes) Remote sensingsatellite imagery acquisition and data analysis Offshore, coastal, and land-based sensing of wave, wind, sediment storm phenomena Storm surge flooding predictions Riverine rainfall flooding predictions Evacuation traffic monitoring management Mitigation Comprehensive community planning Floodplain management Coastal protection and restoration measures Design of wind resistant landscape Design of wind and flood resistant hurricane shelters Preparing historic buildings for hurricanes
13 History of Hurricane Evacuation Studies The ability to inform the general public of an oncoming hurricane (and other forms of natural disasters) has historically been t he key ingredient to avoid a catastrophe. Emerging technologies of storm forecasting and media outlets have been vita l towards disseminating hurricane evacuation information. Given the fact that hurricane ev acuation has the characteristics of non-recurring congestion, together with many variables in stor m characteristics and behavior trends, the ability to plan for the necessary transportation infrastructure is quite challenging. Inte restingly, the United States is one of only a few countri es throughout the world that effectively use mass evacuations as a way of protecting the population along the coastline. (FHWA, 2005) The primary tool for regional areas to deter mine their needed time for evacuation comes from Hurricane Evacuation Studies (HES). During the 1980s the Federal Emergency Management Agency (FEMA) began initiating HES around the count ry to identify the key factors towards a successful hurricane evacuation. A HES genera lly addresses the follo wing five elements: Storm hazard analysis Vulnerability analysis Behavior analysis Sheltering analysis Transportation analysis In March, 1994, FEMA, together with the Nati onal Oceanic and Atmospheric Agency (NOAA) and the U.S. Army Corps of Engineers (USACE), creat ed the National Hurricane Evacuation Task Force to standardize guidelines for H ES around the country. Federal, state, and local governments each
14 participate in these studies, which are updated every 4-5 year s. Guidelines include a comprehensive scope and a multi-regional perspective Some HES reach across state lines when necessary. In 1995, the NOAA published the Technica l Guidelines for Hurricane Evacuation Studies as a reference so that the USACE can effe ctively develop information for translation to local officials. Guidelines were us ed to develop uniformity, terminology and content to a study process that was complex and constantly bei ng refined. (Barret, 2000 and NOAA, 2006) One of the most important com ponents of the HES is the calculat ion of clearance times that identifies how much time would be required for all evacuating vehicles to leave the study area given the roadway infrastructure constraints within t he area. The technical data produced in a HES is used toward creating or updati ng local hurricane evacuation pl ans. (Wolshon, 2001 and USACE, 2006) However, not until recently, did hurri cane evacuation plans emphasize the need to incorporate effective traffic operations. HES use travel demand models to calculate clearan ce times for evacuations. A combination of different evacuation scenarios is evaluated. The evacuation clearance times are based on different combinations of: Seasonal populations for evacuation Socioeconomic factors for what percentage of people evacuate Other populations of evacu ees from other locations Evacuation destinations Different evacuation population bas ed on storm intensity, dire ction, and evacuation zones Other behavioral assumptions
15 Previously, local emergency managem ent personnel were required to develop evacuation plans and traffic operations began a greater involvement beginning in the mid-1980s. Since Hurricanes George and Frances in 1998 and Hurricane Floyd in 1999 transportation professionals have become more involved in the development of evacuation plans. This added transportation expertise has provided assistance forecasting evacuati on travel demand, evac uation traffic operations analysis, and the application of Intelligent Tr ansportation System (ITS) technologies.
16 Hurricane Evacuation Studies Between Different Regions One traffic management tool used for hurricane evacuat ion is the use of contraflow lanes. Many HES throughout the country identify provisions to use contraflow lanes to reduce clearance times in the event of an evacuation. Flori da is one state that has partaken in detailed activities for contraflow research. Most states have a two level approach between local and state agencies. Generally, the local government is responsible for the planning, response, and recovery activities, while the state level emergency management agency coordinates with the local emergency management activities in the coordination of traffic and law enforcement. Fo r example, the Texas St ate Emergency Plan has a general emergency plan, but the local coastal juri sdictions manage the evacuation planning. In Florida, the entire state is vul nerable to hurricanes; therefore, in Florida, the state emergency management agency assumes a greater managerial ro le in developing evacuation plans. However, the evacuation order and management pl an is the responsibilit y of the County law enforcement. The primary difference typically lies between the centralized versus decentralized decision making approach. Table 3 summarizes how the authority to give an evacuation order is provided throughout the hurricane prone stat es. (Wolshon, Urbina, and Levitan, 2001)
17 Table 3 Comparison of Authority Struct ure for Hurricane Evacuations STATE STATE AGENCIES LOCAL AGENCIES Governor State Emergency Management Office National Guard State Police Local Emergency Management Office Mayor Highest Local Elected Official Local Law Enforcement County Judge County President New Hampshire X Massachusetts X X Rhode Island X X X Connecticut X X X X New York X New Jersey X X X X X X Delaware X Maryland X X X Virginia X X North Carolina X X South Carolina X Georgia X X X Florida X X* X Mississippi X X X Louisiana X X Texas X X *Note: The State of Florida has since removed the planned deployment of the National Guard during the course of this research.
18 A comparison of hurricane traffic control plans throughout the Southeaste rn United States was undertaken during this research to learn how th ey compare to Florida. Florida, however, implements several different regional traffic cont rol plans because of the possibility that several coastal areas in Florida may be evacuated for the same hurricane. For example, if a hurricane is approaching from the southwest of the state from the Gulf of Mexi co, the evacuation of southwest Florida counties will greatly impact the evacuat ion clearance time with in the Tampa Bay area because evacuees from south Florida will be using evacuation routes such as I-75 and I-4 to find shelter. This situation emphasizes the importance for regional communication between the different urban areas within Florida in cr eating an effective traffic control plan. Many of the assumptions that are applied in HES are dependent upon evacuee behavior. This behavior creates many different scenarios of congestion for t he road user, not just the characteristics of the roadway it self. Some of evacuees behaviors and lifestyles toward evacuation and corresponding congestion include: (PBS&J, 2006) Participation Rates What percent of the population in differ ent areas will evacuate their dwelling units for future hurricane threats? Evacuation rapidity of response rates How qu ickly will evacuees respond to what local officials are telling them to do? Vehicle usage Of the vehicles available to the households, what percent of those vehicles will be used in an evacuation? While FEMA originated the basic standardization of HES, the consisten cy regarding the authority structure and planning/design processes is relati vely limited between different regions of the country. (Wolshon, Urbina, and Levitan, 2001 and Ga lvan, 2002) For example, the 2001 Hampton Roads, Virginia Traffic Control Plan identifies a criterion of a Category 4 or 5 hurricane needed to
19 implement contraflow lanes for evacuation. Ot her regions around the country do not use that criterion to implement contraflow Each HES should reflect the ev acuation needs for each particular region, so complete standardi zation may not be required. For some areas in the country, such as Hampton Ro ads, Virginia, the use of contraflow is only part of the overall traffic control plan. Some other im pacting factors are as follo ws: (Virginia DOT, 2001) Tolls are lifted for hurricane evacuations Traffic is metered onto the freeway for the I-64 Contraflow Plan Traffic signal timings on evacuation routes are modified from tra ffic management center Phases of implementation are based upon time periods upon the storms arrival Closing of the Ches apeake Bay Bridge Tunnel Agency coordination and responsibilitie s are based upon location of evacuation Detailed maintenance of tra ffic (MOT) drawings are provided for each interchange and major intersection In 2003, the arrival of Hurricane Isabel required an evacuation order for Hampton Roads, Virginia. This provided an opportunity to evaluate the e ffectiveness of the 2001 Traffic Control Plan. Hurricane Isabel made Virginia land fall in Septem ber, 2003, as a Category 2 hurricane. One recommendation identified that t he study area for the Virginia HES should include communities further inland. Additionally, it was identified that more clear ev acuation shutdown procedures were needed. The most notable recommenda tion from the Hurricane Isabel Post Assessment regarding traffic was the emphasis on int egrating emergency management requi rements into the Intelligent Transportation Systems (ITS) architecture at the federal and state level.
20 However, due to Isabel being a Category 2, many local governments reported that relatively few people actually evacuated, or, if they did evacuate, it occurred very la te in the event timeline. Only isolated incidents of roadway blockage or traffic congestion were reported. (USACE, 2006 and PBS&J 2005) The Texas Management & I-37 Conversion Plan also identifies a procedure for agency coordination to implement contraflow. T here is detailed prepar ation and implementation for interstate contraflow. For example, there is a listed crit erion needed to implement contraflow based upon the size/intensity of a storm, antici pated path, storm surge, and the nu mber of citizens prepared for mobilization. Unlike the Hampt on Roads plan, the I-37 Conversi on Plan is expected for a Category 3 storm or greater. The contraflow is discour aged during hours of darkness. The length of contraflow laneage is already predetermined. A dditionally, the number of police personnel required for contraflow is already predetermined. (Hamilton, 2002) Hurricane Rita in October, 2005, was an example of how detailed contraflow planning may be difficult to implement under a real condition. This particular use of contraflow was a reactionary implementation, instead of a pre-planned event. The Hurricane Rita contraflow was implemented on I-45 outside of Houston, Texas and not on I-37 locat ed outside the coastal city of Corpus Christi, Texas. The Hurricane Rita contraflow experi enced extreme congestion at certain bottlenecks primarily for two reasons: The significant number of evacuating people from the major Houston, Texas metropolitan area occurred shortly after Hurricane Katrina Difficulty in the merge/diverge transition areas of contraflow lanes near major interchanges
21 In 1998, only Florida and Georgia DOTs had adopted plans to reverse the flow on their limited access highways to expedite evacuations. By 2005, 11 of the 18 mainland coas tal states subject to the threat of a hurricane had some version of a contraflow plan. Contraflow was implemented for the first time in Georgia, in 1999, during Hurricane Floyd with mixed, but mostly positive, results. An ad hoc implementation (without previo us adopted plans) of contraflow was also improvised in South Carolina during Hurricane Floyd, after a strong public outcry came from evacuees trapped in congestion on I-26 between Charle ston and Columbia, SC. (Wol shon, 2001) To this date, Hurricane George and Floyd are sti ll considered to be the larges t hurricane evacuations in the history of the United Stat es. It was estimated that over four million people evacuated for Hurricane Floyd between the coastal counties of Florida, Georgia, South Carolina, and North Carolina. Figure 4 Hurricane Floyd
22 Shortly after Hurricane Floyd, in 1999, the state of Florida put in motion a detailed set of design plans for contraflow. However, these plans have ye t to be implemented as of 2007. There is little debate that contraflow can significantly increase the outbound capacity for emergency evacuations. However, there are many other el ements to consider in determining its effectiveness. The total costs of contraflow need also be determined in safety risks and manpower requirements, most of which are widely undetermined. Cu rrently, there are no recognized standards or guidelines for the design, operation, and location of contraflow segments. Along with the benefits that contra flow can provide, there are also inherent risks that are associated with the use of contraflow for evacuation pur poses. These risks and uncertainties may include: Overwhelming congestion at end of route Uncertainty of the behavior of individuals Unique storm characteristi cs between each storm event Safety design for guardrails, signage, interchanges, and errant vehicles Labor and time investment during crisis Political consequences if contraflow not required One consideration for contraflow planning is the inverse relation ship between accessibility and capacity. The complete reversal of a highway would create the most amount of available outbound capacity. However, the complete reversal w ould remove all access for any vehicles traveling inbound, some of which may be emergency vehicles ; and those vehicles would be required to use more localized alternative routes. This rela tionship should be consider ed during the development and updating of hurricane evacuation plans.
23 The amount of detail that is cons idered during contraflow planning also varies among the different states. Much of the variation may be related to the specific agency that prepared the plan. The Hampton Roads, Virginia plan which was developed by the Virginia DOT, incl udes great detail in the geometric design and traffic control aspects of the cr oss-over location. The Louisiana plan, which was developed primarily by the State Police, focuses more attention on law enforcement requirements in the contraflow area. Table 4 summarizes the planned Contraflow Routes among the 10 states which currently have them in effect. (Urbina, 2001)
24 Table 4 Planned Contraflow Evacuation Routes State Route(s) Length (miles) Origin Location Termination Location New Jersey 47/347 Atlantic City Expressway 72/70 35 138/I-195 19 44 29.5 3.5 26 Denis Twp Atlantic City Ship Bottom Boro Mantoloking Boro Wall Twp Maurice River Twp Washington Twp Southhampton Pt. Pleasant Beach Upper Freehold Maryland MD-90 11 Ocean City U.S. 50 Virginia I-64 80 Hampton Road Bridge Richmond North Carolina I-40 90 Wilmington Benson (I-95) South Carolina I-26 95 Charleston Columbia Georgia I-16 120 Savannah Dublin Florida* I-10 Westbound I-10 Eastbound SR 528 (Beeline) I-4 Eastbound I-75 Northbound FL Turnpike I-75 (Alligator Alley) 180 180 20 110 85 75 100 Jacksonville Pensacola SR 520 Tampa Charlotte County Ft. Pierce Coast Tallahassee Tallahassee SR 417 Orange County I-275 Orlando Coast Alabama I-65 135 Mobile Montgomery Louisiana I-10 Westbound I-10/I-59 (East/North) 25 115 New Orleans New Orleans I-55 Hattiesburg, MS Texas I-37 90 Corpus Christi San Antonio *Note: I-75 Contraflow between I-275 and I-10 currently under consideration for design in Florida. In most states, including Flori da, the authority to start contrafl ow operations resides with the Governor. Typically, the decision of when to initiate contraflow is made in close consultation with the Department of Transportation, law enforcement, and emergency m anagement officials. Florida, like many other states, monitors real-time traffic conditions with stand-by alertness and will not implement contraflow until traffic volumes warrant their use. All states that have contraflow are also looki ng towards ITS systems for hurricane operations. The most common use of ITS is for moni toring real-time traffic conditions. Florida DOT officials are able to retrieve traffic count informat ion for hourly or 15-minute increm ents during evacuations. Recent enhancements allow data to be assembled and displa yed in tables and graphs to monitor the progress of an evacuation. This traffic count data can also be used together with closed circuit
25 television (CCTV) cameras to provide direct visual confirmation of traffic conditions. In 2004, it was reported that the traffic count data was particularly useful in monitoring the evacuation and re-entry process. The count data was especially useful in coordinating with the stat e of Georgia in making a decision not to open a contraflow lane on I-75 in Georgia. (FHWA, 2006) The Florida DOT also provides th is real-time traffic information to the general public. The Florida DOT website provides access to its statewide net work of real-time traffi c volume and speed data recorders. This information helps traffic officials within the State of Florida decide when, if ever, is the appropriate time to start and end the use of contraflow. Other uses of ITS include highway advisory radio (HAR) and dynamic message signs (D MS). In the hurricane season of 2004, which witnessed four hurricanes travel through Flori da, a combination of DMS, HAR, and *511 phone service was used. (FHWA, 2006) However, the difficu ltly with many ITS applications is that the majority of the infrastructure is located in ur ban areas, while the majori ty of evacuation route mileage is located in rural areas. To initiate contraflow the general following procedure must be complet ed in sequential order: Install traffic control devices and barricades Clear inbound lanes of inbound vehicles Position law enforcement and DOT personnel at assigned locations Most states anticipate that t he above process requires four to 12 hours. The variation in the estimated time is dependent upon the length of the se gment, number of inte rchanges, and number of ramps and merges points along the evacuation route. However, di fferent authorities in Florida previously estimated that 49-96 hours were needed to prepare for contraflow operation. The time was so much longer than other states because Flor ida was required to activate the National Guard
26 forces (prior to 2005) to set up and patrol their loca tions (Collins, 2001). This special consideration in Florida had been the focal point of debate regardi ng the necessity to depl oy the National Guard and the ability to effectively implement contraflow. The actual set up of contraflow has the ability to occur much faster in Florida if it were demanded by the local and state authority structure, which further questioned the necessary deployment of the National Guard. (PBS&J, 1993, 2008) Other contraflow strategies have been reported to require only three hours to establish contraflow, such as the 2004 evacuation for Hurricane Charley in South Carolina (FHWA, 2005). However, it should be noted that a contraflow strategy for Flor ida is naturally more complex than most other hurricane prone states. Most other hurricane prone states are only bounded by the ocean from one side and also have highways that dire ctly intersect the coastline, su ch as I-16 in Georgia, I-26 in South Carolina, and I-37 in Texas, which makes an ev acuation route planning more straightforward. In the case of Florida, the major interstates of I-95 and I-75 run parallel to the coastline, with as little as 100 miles in between them. Florida is susceptible to hurricanes from either coast. That, together with the population density within the state, suggests a situatio n in which numerous evacuation scenarios exist with the capability of extreme c ongestion occurring towards the north end of the South Florida peninsula. Florida officials have adopted a policy that contra flow operations will neither be initiated nor operated during night time. This policy has also been adopted by the Georgia DOT. One reason for this policy may include the fact that reflecto rs and pavement markings are designed to prevent wrong way driving, espe cially during nighttime hours. However, the same officials recognize that some situations may require flexibility dependi ng upon the situation. (Wilmont, 2001)
27 Additionally, the topic of highway work zones was mostly ignored for previous hurricane evacuations. The problems of construction on hurricane evacuation rout es were experienced throughout the southeast United States during the ev acuations of Hurricane Opal in 1995, Hurricane George in 1998, and Hurricane Floy d in 1999. Today, most hurri cane prone states have clauses that require a contractor to ceas e all construction activities once an evacuation order is given, clear all equipment, and open all lanes of traffic (i ncluding the lanes under construction). At the onset of the study, it is expected the contraflow alte rnative with al l outbound lanes should produce most capacity. But is it the most practica l alternative? Previous efforts have shown that there is 70% additional outbound capacity with complete reversal of all inbound lanes when compared to normal operations. The increase of c apacity is less than double due to reduced speed and also driver unfamiliarity on the c ontraflow lanes (Anderson, 2007). Evacuation Demand and Operations Modeling Since the 1970s travel demand modeling techniques have greatly improved, mostly because of the availability of faster computer processors capable of storing and compiling more data. Original travel demand models, such as MASSVAC, were deve loped in preparation for a nuclear disaster. These traditional models were des igned to allow for long range planni ng in situations where origins and destinations were easily determined for only the p eak hours of traffic flow. Today, the capability of hurricane modeling has helped create simula tion programs which are used to model the characteristics of: Evacuation travel behavior
28 Weather Flooding Traffic Flow All evacuations, whether they are caused from hurricanes, floods, fires, or manmade disasters, should consider the following c haracteristics (Barret, 2000): Shape and size of energy source Shape and size of evacuation area Rate of growth of evacuation area Size and socioeconomic data of evacuation population Amount of warning time Level of disruption to the road network Level of danger of the emergency The composition of the evacuating population will al so be influenced by the ti me of day in which the emergency occurs. For example, if the emergency event occurs within an office or business district at 5:00 P.M., the resulting situat ion will differ considerably from w hat would result if the same emergency occurred in the same location at 5:00 A.M. (Ran, 2000). The same is true depending if the emergency occurs on a weekend or weekday. What is unique about the ability to forecast a hurricane as compared to other di sasters, is that there is now much more information available about the storms intensity, speed, direction, and approaching location. However, there are also special challenges asso ciated with a hurricane evacuation. The difficulty occurs in being able to model the entir e roadway network because of the large area of impact and the long period of impacted ti me. This type of situation is typically more appropriate to use for macroscopic models, instead of microscopic models. Additionally, due to the
29 ability of the oncoming storm to damage roadw ays and bridges, the actual road infrastructure cannot be assumed as constant. (Pillai, 2000 and PBS&J, 2005) In creating a hurricane evacuation study there are a minimum of six important modeling steps. (PBS&J, 2000) The development of Evacuation Zone s and Data first identify who is vulnerable and who is likely to evacuate. The trip generation step ca lculates how many evacue es will travel from a traffic analysis zone (or county, city etc.) for a particular storm scenar io. The trip distribution step then determines the destination and t he direction that evacuees will tra vel. The development of the evacuation road network addre sses which roads can accommodat e an evacuation and the carrying capacity for each of those roads. The trip assignm ent determines which routes will be chosen by the evacuees to reach their particular destination. Finally, the step to calculate the expected clearance time determines how much time will be required to clear all evacuees past a chosen cordon line area within the evacuation area. For hurricanes, the Sea, Lake and Overland Sur ges from Hurricanes (SLOSH) model has been widely used to identify flood prone areas. This model was originally dev eloped by the National Weather Service to predict storm surge. Sinc e that time the model has been used to create a classification of hurricane evacuation areas and to identify evacuation routes and emergency shelters given possible flooding scenarios. SLOSH assists in the development of evacuation zones, which are ty pically along the coastline due to their low elevation. Figure 5 shows the locati ons of the evacuation zones in Hillsborough County, Florida. Recent hurricane experiences have demonstrated that major hurricane damage does not occur only along the coastline, as shown in Figur e 6 with Hurricane Charley in 2004, over central
30 Florida. Not surprisingly, there has also been an increase in the number of people who evacuate who do not live in an evacuation zone. These peop le are referred to as shadow evacuees. Over the last 20 years, more hurricane related deaths have been attributed to inland flooding than coastal wind damage and storm surge. Figure 5 Coastal Hurricane Evacuation Zones and Inland Hurricane Damage The hurricane evacuation zones based on the SL OSH model identify coasta l flood prone areas from storm surge, but do not identify in land flood prone areas. Other at-ri sk areas located inland, such as mobile home parks, are also not identified in the SLOSH model. This current practice of determining hurricane evacuation zone s does not identify these types of at-risk locations away from the shoreline. This informati on, together with traffic informat ion, are two major components to consider towards effective hurricane planning.
31 One method of collecting traffic information is t he Evacuation Traffic Information System (ETIS). Hurricane Floyd led to the development of ETIS to facilitate information sharing and planning across state boundaries in the southeast. Several features of the ETIS include integrating traffic count information across state lines, providing behavior st udy updates, and the ability to model partial and full evacuation options. The objective of ETIS is to estimate the necessary and available capacity on the public roadway system. Howeve r, ETIS primarily relies on hist oric traffic counts. (FHWA, 2006) During an evacuation order within Florida, real time traffic conditions are used to determine traffic operation procedures, while historical traffic c ounts are referenced for the planning and preparation of hurricane evacuation plans. Real-time traffic counts are availa ble via the Florida DOT webpage for the general public and are updated every fifteen minutes. The real-time traffic counts can be used for informational purposes to assist the general public with evacuat ion planning to avoid congestions. Also, the real-time counts are used by Florida DOT towards determining the necessity of when to deploy contraflow. Another macroscopic model devel oped originally in the 1980s was the HURREVAC program. HURREVAC uses a Geographic Inform ation System (GIS) to com pare local demographic data with shelter locations and their proximity to evacuation ro utes to estimate the effect of strategic level evacuations. HURREVAC is not necessarily a traffi c model, but is used as a tracking program for Hurricane Evacuation Studies in shelter planning.
32 Additionally, the continuous development of the Hurricane Evacuation Analysis and Decision Support Utility Program (HEADSUP) has been used in Florida to proactively manage traffic operations during an evacuation. (FHWA, 2006) HEAD SUP integrates real ti me traffic data from 27 strategically located traffic counters placed on hur ricane evacuation routes. The data provided from HEADSUP can help coordinate the timing of multi -regional evacuations, such as the Tampa Bay and Southwest Florida regions. Additionally t he model can be used to identify bottlenecks and alternative evacuation routes. Some of the key functions include: Hourly dynamic travel demand forecasts Impact analyses of contra flow lanes Socio-economic statistics on evacuees Map-Based user interface system Travel demand modeling of evacuees on roadway network Archival capability of key events One analysis tool developed for traffic operati on performance was developed by the Oak Ridge National Laboratory and was called the Oak Ridge Evacuation Modeling System (OREMS). This program is based on a CORidor SIMulation (CORSI M) platform to simulate traffic flow during various emergency evacuations. CORSIM platfo rms have also been used by the Florida DOT to comparatively analyze traffic operations for differ ent roadway enhancement projects. The model can be used to estimate clearance times and identify operational tra ffic characteristics. Table 5 summarizes a comparison of currently availa ble evacuation programs that are applied to transportation networks. By nature, the ability to model hurricane evacuation is a very dynamic process. Both the storm and the evacuating public have many variable characteri stics which impact the evacuation process. A
33 dynamic hurricane evacuation model should allow fo r a continuous process, where information from traffic counters, law enforcemen t, and meteorological data can cont inuously update traffic conditions and optimize the systems overall performance. Se veral pieces of inform ation are required to provide a dynamic modeling applic ation (Barret, 2000 and NOAA, 2006): Evacuation route times and performance Predicted evacuation routes and departure times and the resulting evacuation time Monitoring of transportation infrastructure Impacts of different management strategies, w hether they be operational or policy driven
34 Table 5 Comparison of Evacuation Modeling Programs NAME FEATURES LOCATI ONS INPUTS OUTPUTS MASSVAC Macro level Nuclear Power Plant Evacuations Inland Communities vulnerable to contamination Topographic data Wind Conditions Direction Area Speed Magnitude of contamination Sea, Lake and Overland Surges from Hurricanes (SLOSH) Flooding model Developed by National Weather Service All hurricane prone states Hurricane storm data Topographic data Tide data Predict hurricane storm surge Identification of evacuation routes and shelter location HURREVAC Macro level GIS Correlate demographic data to shelter locations and evacuation routes Hurricane prone coastal communities Large urban areas Socioeconomic data Shelter locations Evacuation Route locations Sufficiency of shelter capacity and availability Distance to shelters for population groups Oak Ridge Evacuation Modeling System (OREMS) CORSIM platform Micro level simulation Compare alternative evacuation routes Hurricane evacuation routes Florida Hurricane route locations, capacities, and speeds Behavior data Response rates Destinations Clearance times Simulate traffic flow Forecast evacuee response rates Comparison of alternative evacuation routes Traffic control management techniques Incident Management Decision Aid System (IMDAS) Identify high risk areas Interaction of evacuation plans and traffic operations Florida Topographic data Elevation Behavior data Land use data Traffic volumes Risk prone areas Alternative evacuation plans Traffic operation strategies Evacuation Travel Demand Forecasting System Macro level evacuation model Customized inputs Web-based interface Florida-Georgia Georgia-South Carolina Behavior data Evacuation routes Traffic counters Level of congestion Predicted volumes Cross-state traffic impacts Evacuation Traffic Information Systems (ETIS) Integrating historical traffic count information Partial and full evacuation options Florida South Carolina Historical traffic counts Behavior data Land use data Predicted volumes Hurricane Evacuation Analysis and Decision Support Utility Program (HEASUP) More advanced than ETIS Proactively manage traffic during evacuation Ingest real time traffic data Map based user interface Archival capability Florida Real time traffic count data Road capacities Region specific behavior data Hourly dynamic travel demand forecasts Impact analysis of contraflow Traffic volume forecast
35 The development of a real-time evacuation model is critical to the demand si de requirements because the behavior of individuals cannot be assumed to replicate from previous travel patterns. Therefore, the origin-destinat ion matrices previously used for planning travel demand purposes would not be appropriate. Hum an behavior is not completely predictable under emergency and threatening conditions. Hurricane evacuation does not represent ty pical congestion. Conversely, the supply side of evacuation modeling is also continuously changing. Evacuation traffic conditions are characteristically similar to non-recurring congestion, much like a crash incident on the roadway. Evacuating traffic volumes are much greater than typica l peak hour (and peak directions) conditions, and this sit uation can result in significant va riations in travel times due to congestion. Also, the peak perio d is more spread out than a typical PM peak hour, therefore resulting in a lower K value. A dynamic model should incorporate a regional network with complete information in link conditions for average speed, length, and capacity. T he model should also incorporate changes in link conditions, such as r eduction in capacity due to physical damage of the roadway or crash incidents, and then also simulate alternative traffic management strategies to change the network and recalcul ate levels of congestion once a new equilibrium has been established. (Ran, 2000) Additionally, a dynamic model s hould identify the impac ts on the transportation network from the hurricane itself. A hurricane has the ability to determine which evacuation routes are chosen because of the storms ability to change trajectory and strength. This may be the most challenging input towards creating a dynamic hurricane evacuation model.
36 These combinations of demand, supply, and storm ch aracteristics require unique model architecture for hurricane evacuation. Under ideal mode ling conditions, the evacuee behavior would be completely controlled with optim ized evacuation time. However, minimum evacuation times may underestimate the time actually required for comple te evacuation since the road system is not in a state of equilibrium. Therefore, a key component of a dynamic architecture is compari ng the results from previous step to the difference between the act ual and optimal evacuation time s and determining that they are within an acceptable range. If they are not, t he development of emergency management strategies would be required to improve the per formance. If the model is used in real time, it can be used to gauge the success of management stra tegies. Therefore, the mode l would choose a rolling horizon approach where the Origin-Destinat ion matrices and network data ar e updated and the time horizon is then rolled forward by a length equal to t he roll period. (FHWA, 2006 and Barret, 2000) Summary of Evacuation Procedures in Florida As demonstrated in the previous sections, the State of Florida is considered to be quite progressive when preparing for evacuations from hurricanes. The State of Florida has invested more money toward the research and development of impr oved hurricane evacuation plans and analysis than any other state. This is not surp rising considering the fact that Fl orida is also the most vulnerable state given its extensive ocean coastlin e and low elevation throughout the state.
37 The State of Florida is also a leader in the organizati on and management of hu rricane preparation. As shown in Table 1, Florida is administratively structured so that the Governor serves as the lead coordinator between the different agencies, but the evacuation order is provided by the County law enforcement agencies. T herefore, the coordination between t he Governors office and local law enforcement is vital towards the success of hurricane preparation. Florida has learned from other st ates that developing evacuation pl ans upon the eminent arrival of a hurricane is too late. Each year, the Florida Go vernors office sponsor s the annual Governors Hurricane Conference. Local, regional, and state agenc ies attend this conference to review strategies from previous year s and debate the ability to incor porate new and improved evacuation and hurricane preparation strategies. Admi nistration procedures are also reviewed. Recently, much of the coordinat ion in Florida focuses with st aff involvement at each Countys Emergency Operations Center (EOC). The EOC is considered to be the focal point in determining an evacuation order. Local and state public agencie s meet together at t he EOC, such as law enforcement, public works directors, and the Depa rtment of Transportati on. Adjacent EOCs communicate with each other and the state agencie s upon their determination of evacuation. Most EOCs in each county hol d media press conferences in ear ly summer to assist in the communication with the local public. The purpose of these press conferences is to inform the local public of evacuation schedules, shelter locations, road closures, standard operat ion procedures, etc. Even outside hurricane season, t he State of Florida is busy de veloping new strategies. For example, the contraflow design of I-4 has rec ently been reviewed for consistency with the new
38 widening construction and the abilit y to accommodate additional vehicl es. However, it should be noted that the I-4 Contraflow design plans are be ing updated by Florida DOT to reflect recent capacity improvements. Additi onally, preliminary plans have bee n developed to design I-75 as a contraflow route north of Tam pa Bay. (Anderson, 2007) In Florida, there have been four public agencies which are primarily responsible for hurricane evacuation: Florida DOT Florida Highway Patrol Florida National Guard* Local Law Enforcement and Emer gency Operation Centers (EOC) *However, the National Guard is no longer expected to be involved with contraflow evacuation. This was a result of a recent annua l EOC meeting for State of Fl orida (Anderson, 2007), which coincidentally, is also during the same time period that this research has been conducted. Since the National Guard is no longer part of the contraflow process, contraflow is now designed for a 6-hour setup. Coordination is primarily established between th e FDOT and FHP. The call for contraflow originates from the Governor. All logist ical operations originate at State EOC center. It is expected that the contraflow request originate upon c ongestion from a local offici al to the governor. Upon evacuation and contraflow activation, the Dist rict EOC Director assumes managerial control of FDOT operations, not the district secretary. All operations on th e Interstate are managed by FDOT and FHP during contraflow activation. The local authorities then help provi de law enforcement at the interchanges and local roadways lead ing to the contraflow routes.
39 The Florida DOT is responsible for developing any contraflow evacuation plans. Also, the FDOT furnishes the necessary resources for contraflow such as cones, barricades, signs, etc. The Florida Highway Patrol implement s and operates the contraflow plan when it is activated. The highway patrol provides monitoring personnel at locations such as interchanges, on-ramps, and other crossover locations during the evacuation. The decision to call a hurricane evacuation in Florid a now is determined at the local county level. Prior to Hurricane Opal in 1995, t he State maintained primary respons ibility, but has since modified that policy. The Count y Sheriffs department is responsib le for coordinating local hurricane evacuation procedures with State agencies. C ontraflow is implemented on state facilities and monitored by state agencies, while local law enforcement is responsib le for monitoring local roads. These procedures are constantly being updated within the State of Florida; however, there are still opportunities for improvement in being effect ively prepared for an oncom ing hurricane. This dissertation addresses that need to identify improvements toward hurricane evacuation, particularly towards identifying strategies for the use of contra flow lanes. Therefore, this research addresses the basic question, Is Contraflow a real feasible alternative for hurricane evacuation in Florida? The expected benefits associated with contraflow are examined together with the logistical requirements to answer this question.
40 RESEARCH METHODOLOGY The methodology identified in th is dissertation is to evaluate existing procedures and traffic management techniques in Florida. Special emphasis is plac ed towards the application of contraflow lanes within the state as an effect ive traffic management tool to increase available directional volume capacity. This study is unique in that the Measures of Effectiveness (MOEs) are evaluated for both a measure of available capacity fo r traffic operations and a measure of logistical feasibility. The following checklist strategy summarizes the pr ocess that was undertak en for the dissertation: Define the problem to be evaluated Research development of hurricane planning process Identify current Florida evacuation procedures Develop performance measures for analysis Identify contraflow design alternatives Identify alternatives for contraflow logistical procedures Explain data assumptions and data variables Analyze results of performance measures o Improved Capacity o Required Infrastructure o Required Personnel o Speed Variation o Logistics o Delay/Congestion
41 Development of suggestions/conclusions Identify opportunities of future research Describe observation of dissertation procedures While the study is directed towards hurricane evac uation procedures in Florida, several aspects of this study may be applied within ot her regions of the Un ited States. Also, this research may be applied towards other types of evacuation planning. The discu ssion of applicability of this dissertation is elaborated under a separate chapter following the results and the development of suggestions/conclusions. It was hypothesized during the beginning of this re search that the contraflow implementation process outlined in Florida requir ed too much activation time to be an effective evacuation tool. Therefore, new techniques have been developed and analyzed to improve their anticipated effectiveness and possible implementation. Development of Contra flow Alternatives The development of contraflow alternatives be gan with a review of established contraflow procedures. This review was undertaken by a combination of methods. One method was by interviewing employees that represent the follo wing emergency planning agen cies and companies: Florida Department of Transportation Tampa Bay Regional Planning Council PBS&J Hillsborough County Emergen cy Operations Center Citrus County Emergency Operations Center
42 State of Florida Emer gency Operation Center State of Florida Governors Office Florida Department of Community Affairs The Director of each of the Em ergency Operations Center was c ontacted for an interview. The Planning Director of t he Tampa Bay Regional Planning Council was also interviewed as the local affiliate of the Department of Community Affair s. The Emergency Planning Coordinator was also interviewed and provided subsequent informati on representing the TBRPC. This information consisted of providing copies of the Tampa Bay Hurricane Evacuation Studies of 2006 and 1998. The Emergency Operations Manager of Florida DOT District Seven was interviewed to provide information regarding the policies and process standard s currently adopted by the State of Florida. Information regarding the contraflow implementatio n process was also discussed in detail with Florida DOT staff. This information consisted of reviewing contraflow design plans, providing logistical and promotional videos and pamphlets fo r public information. Florida DOT staff also helped provide traffic count data. Staff from PBS&J assisted with providing inform ation regarding previous and current hurricane planning processes within Flor ida and around the Southeast United States. PBS&J has conducted numerous hurricane evacuation studies for local governments, and holds det ailed information on how the profession of hurricane planning has emerged for the past 20 years.
43 Provided below is a sampling of questions t hat were asked between the different conducted interviews: Please summarize your current hurricane evacuation planning efforts. How have these planning efforts changed over the recent years? How does contraflow impact your evacuation planning efforts? If contraflow is implemented, what are the responsibilities of your agency; and how do you coordinate those responsibilities with t he other emergency planning agencies? What has been learned from other regional planning efforts and contraflow operations from other regions of the country, and how has your agency responded to those lessons learned? What alternatives of contraflow have been considered during your evacuation planning? How are you involved with media campaigns or other methods of educating the general public towards contraflow and evacuation preparation? How frequently are your planning efforts updated? How is success defined within your agency regarding hurricane evacuation planning? What suggestions toward future planning efforts regarding hurricane evacuation and contraflow should be considered? The answers from the questions abov e provided the information from the conducted interviews to establish the different performanc e measures and determine the m easurements of effectiveness. Additionally, this information was collaborated between the diffe rent sources and determines the weighting system between the different performance measures, as described in the section labeled Alternative Method of Weight ing Performance Measures. Much of the information received from Florida DOT was prioritized in the weighting system, since Florid a DOT is considered to be the implementers, as well as the manager, of contraflow activities.
44 The annual Florida Governors Hurricane Confer ence located in Ft. Lauderdale, Florida was also attended. The purpose of the technical sessions and the workshops from this conference is to provide new developments in t he emergency planning practice th roughout the State, as well as other hurricane prone states. Currently, four different variations of contra flow have been identified. Table 6 summarizes the different strategies of contraflow between the different states. Prev ious studies have estimated that a full four-lane outbound contraflow may provide up to a 70 percent increase in capacity over a conventional two outbound lane configur ation. Another strategy to improve capacity is to have a single inbound lane reversal, which is estimat ed to increase outbound lane capacity by about 30 percent on a four lane grade separ ated highway. Additionally, a stra tegy that uses the outbound left shoulder lane as an additional ou tbound lane is estimated to incr ease outbound capacity by eight percent (USACE, 2006). The capacity increase depen ds on the width and condi tion of the shoulder. The use of the shoulder lane also prohibits the exclusive use of emergency vehicles.
45 Table 6 State Comparison of Contraflow Strategies Strategy New Jersey Maryland Virginia North Carolina South Carolina Georgia Florida A labama Louisiana Texas All lanes outbound X X X X X X X X X One lane reversed, one lane inbound for emergency/service vehicle entry only X X One lane reversed, one lane inbound for traffic only X X One lane reversed and use of outbound left shoulder lane X Figure 6 Typical Cross Section of E ach Contraflow Strategy Even though Florida has not yet implemented contrafl ow lanes, it has the most extensively planned use of contraflow operations, with seven identified sections. The first contraflow design plans in Florida were originally crea ted for I-4 located between Tam pa and Daytona Beach in February
46 2000. This section of I4 has been previously considered to be the best candidate for contraflow to be activated. (Engerski, 2007) In total, approx imately 750 miles are planned for possible contraflow use in Florida. An additional section is cu rrently under design for I-75 between the North I-275 interchange and I-10. Additional contraflow plans were recently under development in Delaware, Virginia, Louisiana, and Mississippi. This photo displays how a shoulder lane may not provide continuous capacity, and lead to merging congestion for hurricane evacuation. Figure 7 Bridge Span Safety Consideration for Shoulder Lane In summary, the primary contributors of tec hnical data have been the Fl orida DOT and the Tampa Bay Regional Planning Co uncil (RPC). This is in addition to the interviews conducted with the public agencies. The following sources of data were obtained for quantitative data necessary to measure the capacity analysis: Florida DOT Real-Time Tra ffic Information Website Tampa Bay RPC 2001 Hurricane Evacuation Study Tampa Bay RPC 2006 Hurricane Evacuation Study Update Florida Traffic Information Traffic Count CD (2006 FTI-CD) Florida Contraflow Design Plans
47 One of the tools that the Florida Department of Transportation uses to inform the traveling public of real time traffic conditions is their public website. The address for the web site is http://www3.dot.state.f l.us/trafficinformation/ and there is another w eb site available at www.511tampabay.com This is a reliable so urce of data to obtain speed and traffic information for hurricane evacuation purposes. Drivers interested in knowing traffic congesti on levels during an evacuation are able to access this website to i dentify which evacuation routes are experiencing congestion or incidents that would reduce the average travel speed. Although the decision whether or not to evacuate may be predeter mined by a local resident, drivers may use the information to help decide when they choose to evacuate, and/or which evacuation route to use. Congestion levels and average travel speeds are part of the information available on the web site in both graphical and tabular form. Fi gure 8 shows the informat ion available provided to the traveling public on the website.
48 Figure 8 Florida Real Time Travel er Information Website Other public websites have been as identified available to research Contraflow and hurricane evacuation procedures in Florida, such as: www.teachamerica.com www.onewayflorida.com www.fl511.com www.dot.state.fl.us www.tbrpc.org One task that was undertaken was to evaluate the traffic volume growth that has been experienced on the study location of I-4 in eastern Hillsbor ough County. The purpose of this effort was to demonstrate how excess capacity that would have been previously avail able during an evacuation
49 has now been consumed for regular commuting traffic. The most recent editi on of the Florida DOT Florida Traffic Information (FTI)-CD was obtained for data to identify t he historical growth. This FTICD provides Annual Av erage Daily Traffic (AADT) volumes for each traffic count location in the state of Florida. For this particular count stati on on I-4, data has been avai lable since 1970. Data was obtained for the count location on I-4 just east of the Park Road Interchange, (count station 0084 located at mile marker 30.300). Figure 9 provides a map of the count station locations in east Hillsborough County. Note: Count station used for analysis identified in yellow. Figure 9 Florida DOT Traffic Count Location Map The most recent data available identified an average daily volume of 104,500 vehicles per day. This is compared to an average daily volume of 17,000 vehi cles per day in 1970. It should be noted that the capacity of study secti on of I-4 was increased from four l anes to a six lane typical cross
50 section in 2003 in eastern Hillsborough County. These data suggest that while I-4 has increased capacity, I-4 also experiences more congestion on a daily basis than it did 35 years ago, which then suggests that I-4 would be susceptible to extreme congestion during a hurricane evacuation. The peak hour of travel on the study section of I-4 curr ently represents 8.24% of the total daily volume. Figure 10 summarizes the historical growth of daily traffic volumes for the study area. Figure represents when six-lane capacit y expansion on I-4 became available. Figure 10 Daily Traffic Volume History The researcher participated in the initial I-75 contraflow reviews. These meetings served as design workshops for the participating agencies of Highway Patrol, Department of Transportation, and local law enforcement. The attendance at these meet ings assisted in understanding the development process of contraflow design plans. A design re view of the I-4 Contra flow Design Plan for its anticipated effectiveness (if and when the contraflow is implemented) was also conducted. The I-4 Traffic Volume Growth on I-40 20,000 40,000 60,000 80,000 100,000 120,0001 97 0 19 7 3 19 7 6 19 7 9 1982 1985 1988 1 99 1 1 99 4 1 99 7 20 0 0 20 0 3YearVolume (Vehicles per day)
51 Contraflow Design Plan was the fi rst one developed in Flor ida and is considered to be the first likely roadway to be used for contraflow during an evacuati on. (Anderson, 2007) Site visits of I-4 were performed during this research to demonstrate where the infrastructure is currently available to conduct a contraflow situation. Note: When the median is not used as a crossover location, a movable concrete median is installed. Figure 11 I-4 Crossover Locations for Contraflow
52 Development of Performance Measures The six performance measures are as follows: Improved Capacity Required Infrastructure Required Personnel Speed Variation Logistics Delay/Congestion Improved Capacity is a performance measure based upon the available vehicle throughput. Each contraflow alternative was evaluated on how mu ch more capacity was created. This analysis evaluated improved capacity for two separate measurements: Evaluating average speed for each alternative assuming a standardized service volume Evaluating available capacity for each al ternative assuming a standardized speed For the first part of the improved capacity performance measure the LOS E service volume capacity was used to compare the average travel speeds. The 2002 Florida Quality/Lev el of Service Manual published by the Florida DOT was referenced to identify a generalized LOS E service volume. For a six-lane urban freeway, t he peak-hour, peak-direction LOS E serv ice volume is 6,150 vehicles per hour. The total saturation flow was derived by adding the traffic volumes from the regular lanes together with the volumes from the contra flow lanes. The average speed from the total saturation flow was then evaluated and reported from Sychro/SimTraffi c. The average speed was a weighted average
53 between the regular outbound lanes and the contraflow lanes. For the purpose of hurricane evacuation, the contraflow alternative which cr eates a greater average s peed is considered to be more effective to quickly evacuate the general public. The second method of the improved capacity performance measure was based upon identifying which alternative could produce the greatest thr oughput of vehicles, or the greatest volume during a hurricane evacuation. This evaluat ion would identify the greatest density prior to creating excessive congestion where vehicle speeds would be slow. Therefore, the average speed was assumed at approximately 30 mph to evaluate the maximu m throughput for each alternative during an evacuation. The required infrastructure performance measure is based upon the amount of materials and infrastructure required to impl ement a contraflow operation duri ng hurricane evacuation. The primary type of additional infrastr ucture is the orange c ones needed to delineate traffic from their desired lanes and routes. It is assu med that the best contraflow al ternative for this performance measure will require the least amount of additional infrastructure. The required personnel performance measure is also bas ed upon the quantity to effectively implement the contraflow operation. Similar to the required infra structure, the fewer number of required personnel that are required to operate a contraflow operation, the more favorable it is scored. However, it is difficult to obtain a firm cost of the different alternatives, and the cost associated with additional personnel. For example, how does one measure the cos t/benefit ratio when an analysis
54 would require the cost of FDOT/FHP overtime pay co st versus the benefit cost of evacuation? That is why this analysis is not an economical benefit/cost emphasis. Speed variation is considered a performance m easure primarily due to safety The more variation in speed during an evacuation can create a safety risk, mostly due to side swiping and/or rear end collisions. The concern is m agnified during an evacuation, bec ause the roadway is operating at capacity; and when there is a cras h, the resulting conges tion delay is much greater during a time when throughput is most importan t. Therefore, this performance measure is rewarded by the consistency, or the lack of speed variation. Additionally, the speed variation was evaluated for each lane gro up. However, only the outbound evacuation direction was evaluated for speed variation (not the inbound direction). The logistics performance measured is measured by how much set up is required to implement contraflow. Also, part of the logistics is the amount of effort required to convert the contraflow lanes back to regular operation. This performance measure is related to the required personnel and the required infrastructure performance measures. The amount of cooperation and time for set up is a key component of this per formance measurement. The amount of set up and breakdown time is considered o ne of the most straight forward measurements of logistics This is because it assumes the coordination of evacuation personnel and logistics to prepare for each contraflow alternative. Other logistic al considerations, such as operating Highway Advisory Radi o (HAR), Variable Message Signs (V MS), road rangers, etc. are expected to be relatively constant between each alternative.
55 The delay/congestion performance measure is directly related to the effectiveness of an evacuation. The amount of delay inhibits the free flow of vehicles. It is a quantitative measure that can be evaluated by seconds delayed, speed differentiation from free flow c onditions, and/or the number of vehicles unable to be served by the highway during peak conditions. The delay/congestion performance measure can be evaluated using Sy nchro/SimTraffic modeling software. Evaluate Contraflow Logistics The ability for contraflow to serv e as an effective evacuation tool in Florida may currently be most limited by some of the originally identified logist ical procedures. The following is to be accomplished while evaluating the logistic s to implement contraflow: Determine the Need of the Florida National Guard Identify the Time Needed to Activate Contraflow Compare Logistics to Other States Evaluate Authority Structure Unlike any other state that has adopted contraflow lanes, the Stat e of Florida previously required the activation of the National Guard. The purpose of the National G uard was to assist local law enforcement officials. Their res ponsibilities would include monitoring travel conditions at locations such as interchanges and helping remove disabled vehi cles from the travel lanes. However, it had been reported that the National G uard may require up to 96 hours to be completely activated and deployed to the evacuation routes. (PBS&J, 2000)
56 Ninety six hours is the equivalent of four days, and is too long of a time to initiate an effective evacuation. Typically, an evacuation order is given two to three days prior to the expected arrival of a hurricane; therefore, the Nationa l Guard would likely arrive too late to be effective. Thus, an evacuation order would need to be called approximately six days prior to the hurricane making landfall. Six days is currently beyond the capability to accurately forecast a hurricanes trajectory. This research evaluated the necessary logistics for contraflow deployment. The procedures used by other neighboring states were reviewed for their effectiveness and applicability to Florida. Other states, such as Texas and Georgia, have the ability to activate contraflow within a 7-15 hour time frame. Alternatives to improve Fl oridas ability to quickly activate contraflow, such as removing the dependence of the National Guard, have been identifi ed. Some of these recommendations also may include modifying the authorit y structure in Florida summariz ed in Table 1. The improved measurement of time to activate contraflow w ould be considered as one meas ure of effectiveness.
57 Perform Capacity and Travel Time Analyses The researcher started the contra flow analysis by reviewing existing Hurricane Evacuation Studies. The assumptions and methodology were review ed for appropriateness in determining the anticipated traffic volumes for particular evacuati on scenarios. The Tampa Bay Region Hurricane Evacuation Study is periodically updated for t he Tampa Bay Regional Pl anning Council and the Florida Department of Co mmunity Affairs. Source: 2006 Tampa Bay Hurricane Evacuation Study Figure 12 Components of Evacuation Time The regional population is factored into the evac uation clearance times. Some scenarios also incorporate evacuees from Southwest Florida. The referenced population assumptions for Hillsborough County are prov ided below (PBS&J, 2006): Year 2006 Permanent P opulation 1,176,781 Permanent occupied dwelling units 509, 553
58 Mobile homes 34,041 Tourist/seasonal units 29,677 Year 2011 Populati on 1,301,648 People per permanent unit 2.31 Vehicles per permanent unit 1.64 Level of Service E traffic volumes were used as a constant variable in creating a comparative format of analysis for the different contraflow desi gn plan alternatives. Expected variations between the time of day and variations between different days of the week that influence demand of the roadway were not analyzed separately. Instead, the analysis was undertaken to evaluate the available supply, or capacity, of the roadway. Th is was done so that the impacts from the different contraflow could be evaluated in a more straightforward approach. A typical cross-section of grade separated highway in Central Flor ida was used as a demonstration facility to comparatively analyze the alternatives Interstate 4 between Tampa, Florida and Polk County, Florida was used as the demonstration facility. The study area location was located in East Hillsborough County, just west of the Hillsborough/Polk County line. The study area location is shown in Figure 13.
59 Note: Cross-section study location identified by dashed red circle. Figure 13 Study Area Location This typical cross-section study ar ea can help this research study in its applicat ion to other regions in the Country. The four differ ent versions of contraflow previ ously identified have been analyzed comparatively for their effectiveness. This research study incorporat es incident management techniques that impact the capacity of a highway. These incidents include frict ion factors such as broken dow n vehicles within and outside the travel lanes. Other friction factors may incl ude narrow travel lanes, narrow shoulder lanes, poor pavement conditions, etc. The capacity analysis for the differ ent contraflow alternatives was undertaken using the most recent released version of Synchro, version 7 This format allows the direct benefit analysis for the alternatives. Additionally, simulation analyses we re undertaken for each of t he different contraflow
60 alternatives using the most recent version of SimTraffic. Graphical illustrations of SimTraffic were overlaid recent available aerial photography for the study area. Development of Suggestions/Conclusions The Synchro/SimTraffic capacity software was used to calculate the capacity Measure of Effectiveness (MOE) for the different contraflow alternatives. T he different MOE considered are as follows: Average Travel Speed Total Throughput Speed Variation Level of Service Volume Saturation Flow Rate Other measures of effectiveness we re measured in terms different from the above, but were also considered in the development of conc lusions. These measures include: Implementation time to construct Required manpower and equipment Safety risks Implementation time to de-constr uct back to normal operations Number of personnel required The data for the MOEs described abov e were from a combination of interviews and the review of state/county administrative pr ocedures. These aforementi oned MOEs have been grouped together to create a matrix of alternatives. A sample matrix comparing the MOEs is provided in Table 7.
61 The matrix is summarized between the six different performance measures. The improved capacity is measured on a basis of volume, most typically in terms of vehicles per hour. The alternative, which accommodates the most vehicles per h our, received the highest score. Required Infrastructure consists of items such as cones, barriers, signage, safety enhancements, etc. that are required to modify the travel lanes into a contraflow format. The alternative which requires the least amount of additional infrastructure was rated the highest score. Required personnel are a measurement needed to monitor and m anage each contraflow alternative. This column is also measured in terms of the number of different public agencies re quiring activation and how many non-local personnel require activation. The alte rnative which requires the fewest number of personnel and least number of public agencies requir ing activation will receive the best score. Speed variation is considered to be an indicator of safety and is measured in terms of speeds (miles per hour) which deviate from the average speed. The output reports from the Synchro/SimTraffic modeling platform was the basis for evaluation. Each performance meas ure that was evaluated with Synchro/SimTraffic was completed using methodol ogies consistent with the most recent edition of the Highway Capacity Manual (HCM). The alter native with the most consistent speed received the best score. Logistics was predominantly measured from conducting interviews during the study. The alternative with the most simplistic logistics received the be st score. Factors such as accessibility, emergency vehicles, etc. are consider ed into the analysis.
62 Each performance measure, or criterion, was sca led. This method allows an alternative to be scored accordingly by how dominant, or inferior, it compared to the other alternatives for each performance measure. Initially, each performance measure had equal weigh t. This assumes that each performance measure has a uniform importance. The conclusi ons were identified based upon this assumption. However, an alternate approach wa s also undertaken where different performance measures were assigned different weights. Th is approach is addressed under a separ ate chapter later in the report. Table 7 Matrix Format Summary Contraflow Alternative A Normal Operation B Normal Outbound +1 Contraflow C1 Normal Outbound +1 Shoulder +1 Contraflow C2 Normal Outbound +2 Contraflow D Normal Outbound +Complete Contraflow Improved Capacity -----Required Infrastructure -----Required Personnel -----Speed Variation -----Logistics -----Delay/Congestion -----Average Score -----
63 Each considered factor identified for each co lumn has been presented in various charts and graphics to compare the analysis for each alternat ive. Each column has then been comparatively summarized. The result of each alternative is summarized in the matrix format to determine the most appropriate form of contraflow for hurricane ev acuation. The contraflow design alternative with the highest average scoring between the columns will be considered as t he best alternative. Suggested modifications (if any) to the implement ation procedures were dev eloped to help improve the ability of contraflow lanes to serve as an effe ctive hurricane evacuation strategy. This research also facilitates the development of preliminary design guidelines for c ontraflow lanes within the state of Florida.
64 DATA ASSUMPTIONS The calculated 2006 and projected 2011 clearanc e times from the TBRPC Hurricane Evacuation Study are based on the current and projected ev acuation roadway network, storm intensity, evacuation population, and the behavioral response ra te, which were adopted into the contraflow analysis. Other data assumptions more pertinent to the effectiveness of contraflow evacuation are described below: Driver behavior and evacuee assumptions Roadway characteristic assumptions Traffic Volume Assumptions Sources of Data This dissertation collected data from several differ ent sources. The data we re collected from local, state, national, and international resources. The Florida DOT, Tampa Bay Regional Planning Council, Literature Sources, and Emergency Oper ation Centers represent ed the four primary sources of data. Each of the four sources pr ovided different types of data, as described below:
65 Table 8 Sources of Data Florida Department of Transportation o Contraflow designs and logistics o Level of Service methodologies Tampa Bay Regional Planning Council o Hurricane Evacuation Studies o Development of traffic volumes o Behavioral Survey Literature Reviews o Contraflow alternatives o Examples from other states State and Local Emergenc y Operation Centers o Evacuation procedures o Contraflow determination Driver Behavior and Evacuee Assumptions The clearance time is considered as the necessary time to clear the roadways of all evacuating vehicles from the region duri ng an approaching hurricane. The clearance time should not be confused for the time required for one vehicle to ev acuate. The time begins when the first vehicle begins evacuation and ends when the last evacuatin g vehicle arrives at a predetermined point of safety. The 2006 HES assumes the point of safety at I-75 and Floridas Turnpike interchange near Wildwood, Florida for northbound evacuees. Or lando is determined as the eastbound point of safety. No safety location was assumed for vehicles evacuating to the south. The Tampa Bay HES evaluates several different sc enarios. For the purposes of this study, the scenario which includes a full scale evacuation a ssociated with an oncomi ng Category 5 storm was
66 used. Standard assumptions, such as typical seasonal populations, auto ownership, trailers, and heavy vehicle percentages were used. Traffic volumes and the distribution patterns of evacuees were adopted from the existing Florida Standard Urban Transportati on Modeling Structure (F SUTMS) and Cube/Voyager protocol travel demand modeling software that is used for the Ta mpa Bay HES. Adopted socioeconomic data and land use intensities for the traffic analysis zones fr om the HES were used. Therefore, the travel demand modeling structure was adopted and applied for the following parameters: Anticipated traffic volumes on the evacuation routes Anticipated clearance times A time distribution for evacuation was not assu med, such as hours of the day and days of the weeks. These assumptions, and other assumptions that would affect t he travel demand for the highway, would be the largest source of uncertain ties. Rather, the analysis is based upon a supplyside evaluation of available capacity. This provides a more straight forward ability to evaluate the different alternatives and minimize the influence of demand uncertainties. Previous HES documentation assumed 100% evacua tion for locations within the SLOSH storm surge area. All mobile homes in both coastal and inland zones are assumed to evacuate. However, most people know their intentions of evacuation and their intended refuge. 70-80% of vehicle usage was assumed for household, dependin g upon specific risk area. 55% of evacuees plan to go to homes of friends and relatives. Recent behavior surveys doc ument a greater tendency of local evacuations, or evacuations of shor ter distances. The behavioral assumptions and the
67 precise parameters used for each county and zo ne for the selected hurricane scenario was referenced from Appendix C of the 2006 Tampa Ba y HES Transportation Model Support Document. The use of clearance time is mostly used for deter mining the requirements and logistics of public shelters. The clearance times from the HES is not referenced by the FDOT in preparing hurricane evacuation contraflow logistical planning and set up (Hibbard, 2006). However, the information does provide helpful insight into the travel demand characteristics and driv er behavior during an evacuation. Roadway Characteristic Assumptions Law enforcement personnel were assumed to a ssist at bottleneck locations. The evacuation network includes facilities with sufficient elevat ions, minimal tree coverage, sufficient shoulder widths, and roads along existing hurricane evacuat ion plans. A link-node system was developed where links are the roadway segments and a node wa s identified at a location where two roadways change in characteristics. Directional traffic service volumes of a Level of Service E were established for each link. This was the volume used to compare each of the contraflow alternatives. The LOS E peak hour, peak direction volume fo r an urban, six-lane divided freeway is 6,150 vehicles per hour. LOS E conditions are rarely reac hed during evacuations. Actual fl ow rates are typically lower. However, there can be temporary variations of tr affic volumes from demand vari ations. To ensure a
68 more straight forward evaluation of the alternativ es to minimize the impact of demand fluctuation, a supply-side evaluation of the av ailable capacity was undertaken. Other important roadway network assumptions include: All vehicles will evacuate prior to sustained tropical force winds (39 mph). Traffic signal timings will be actuated to provide the most green time for northbound and eastbound movements away from the coast. Vehicles in distress on the network will be removed quickly through aggressive traveler incident management. Drawbridges will be locked down at least 12 hours prior to the arrival of hazardous conditions by the U.S. Coast Guard. It has been observed that during an evacuation, the rate of traffic volume growth observes a relatively minor peak. For example, the K fa ctor observed during t he peak hour of a 24 hour evacuation period may be 0.05-0.07. The typica l K factor for the af ternoon peak hour is approximately 0.09-0.10. The reason for this situation is because of an evacuation period being anywhere between one to two-and-one-half days, depending upon the charac teristics of the hurricane.
69 Figure 14 Evacuation Network
70 Figure 15 Directional Service Volume
71 Within the regional area, the majority of the critical locations are located in Tampa. Two of the six most congested locations expected during an evacuat ion are located along I-4. The most Critical Roadway Sections/Interchanges in Hillsborough County were previously identified to be: I-275/1-75 interchange I-275/I-4 interchange I-275 northbound on ramps I-4 eastbound on ramps SR580/Veterans Expressway interchange Gandy Boulevard Crosstown Expressway Interchange Interstate-4 has been considered to be the most likely candidate for contraflow. The adopted I-4 contraflow design plans identified a typical cross section changeover. Recently, I-4 was widened as a typical six-lane rural cross se ction between Tampa and Orlando. The primary crossover location is planned at the major interchanges, such as I-4 & I75. Also, the recent effort to install median guardrails along Florida inters tates has impeded the ability for the contraflow design and implementation plans. The si x-lane widening of I-4 was not designed to accommodate shoulder riding. (Anderson, 2007) Previous contraflow des ign plans from when I-4 was still a four lane crosssection is provided belo w (Yik Lim, 2003).
72 Figure 16 Previous I-4 Contraflow Design Plans at SR 417 Traffic Volume Assumptions This research has been completed with two basic assumptions regarding tr affic volumes. The previous subsection describes how the traffic vo lumes were adopted from a Generalized PM Peak Hour Level of Service E service volume for t he basic three lanes in the outbound direction.
73 Therefore, the measures of effectiveness we re evaluated from an adopted traffic volume and corresponding saturation flow rate of vehicles for each evaluated contraflow alternative. For example, consistent volumes were assumed for both non-contraflow and contraflow conditions. The same volumes were assumed for each contraflow alternative, so that the different MOEs, like average travel speed, could be evaluated under a constant baseline comparison. Then the simulation of traffic operations was run using Synchro/SimTraffic version 7. The second part of the capacity analysis was evalua ted differently, in which each contraflow was evaluated to identify the maximum volumes that could be serviced. Therefore, MOE for this scenario changed so that the service volume was used to comparatively evaluate each alternative. The capacity analysis using Synchro/SimTraffic, version 7 was completed using methodologies consistent with the most recent edition of the Hi ghway Capacity Manual (HCM). A lane utilization factor of 1.0 was assumed when the volume/capacit y (v/c) ratio for each l ane group approached 1.0. The traffic volume assumptions were most influential for the Improved Capacity and the Delay/Congestion performance measures. Other influencing factors are discussed in the following chapter.
74 RESULTS As previously discussed in the research methodolog y, the evaluation of the different contraflow alternatives was determined upon the usage of six different per formance measures. Each contraflow alternative is comparatively scored for each performance measure, and each performance measure has initially been provided an equal scale. The lowest scored alternative is considered to be the best and most feasible alternative for implem entation. The six performance measures are as follows: Improved Capacity Required Infrastructure Required Personnel Speed Variation Logistics Delay/Congestion
75 Improved Capacity Improved Capacity is a perform ance measure based upon the available vehicle throughput. Each contraflow alternative was ev aluated on how much more capac ity was created. As earlier described, the analysis evaluated improved c apacity for two separate measurements: Evaluating average speed for each alternative assuming a standardized service volume Evaluating available capacity for each al ternative assuming a standardized speed For the first part of the capacity performance m easure the LOS E service volume capacity was used to compare the average travel speeds. The 2002 Fl orida Quality/Level of Service Manual published by the Florida DOT was referenced to identify a gener alized LOS E service vo lume. For a six-lane urban freeway, the peak-hour, peak-direction LOS E se rvice volume is 6,150 vehicles per hour. Therefore, each contraflow alternative for this firs t series of evaluation was held to a constant total hourly volume of 6,150. The i deal saturation flow per lane was then identified for the regular outbound lanes. For Alternative C1, which uses t he shoulder lane for outbound direction, the ideal saturation flow per lane was reduced to reflect a reduced lane width of 10 feet, and other friction factors of road debris, different pavement type, and rumble strips located al ong the shoulder lane. The ideal saturation flow per lane for the cont raflow lanes was also referenced from the 2002 Florida DOT Q/LOS Manual. However, traffic se rvice volumes for an uninterrupted, undivided highway were assumed for the alternatives wh ich experienced opposing traffic, such as for
76 Alternatives B, C1, and C2. A five percent capac ity reduction was applied to account for the lack of a median within the contraflow lanes (to re flect the influence of oncoming traffic). A constant opposing volume of 400 vehicles per hour was assumed for the inbound direction during the evacuation. This volume was assumed for eac h alternative, except fo r Alternative D, which consists of complete reversal. Therefore, t he assumed 400 vehicles would need to access other local, parallel facilitie s for Alternative D. The total saturation flow was derived by adding the traffic volumes from the regular lanes together with the volumes from the contra flow lanes. The average speed from the total saturation flow was then evaluated and reported from Sychro/SimTraffi c. The average speed was a weighted average between the regular outbound lanes and the contraflow lanes. The capacity analysis was also based upon referencing several different empirical formulas from the most recently published edition of the Highway Capacity Manual (HCM), version 2000. Specifically, the referenced chapters and formulas for this analysis were derived from Chapter 22 Freeway Facilities, Chapter 23 Basic Freeway Segments, and Time-Space domains. The flow rate of a basic freeway segment was referenced toward evaluat ing the improved capacity and the delay/congestion performance measures. The Highway Capacity Manual was referenced toward determining the flow ra te. The flow rate was based upon the formula, in which: v(p) = V / (PHF N f(hv) f(p))
77 Where: v(p) = 15-min passenger car equivalent flow rate (passenger cars/hour/lane) V = hourly volume PHF = peak-hour factor N = number of lanes f(hv) = heavy vehicle adjustment factor f(p) = driver p opulation factor For the purpose of hurricane evacuation, the contra flow alternative which cr eates a greater average speed and the greatest flow rate is considered to be more effective for quickly evacuating the general public. It should be noted that the Flori da DOT has operational pol icies about contraflow (when and if it were to be enacted). For example, trucks are unabl e to travel on shoulder lanes, as provided on Alternative C1. Also, trucks are not permitted to us e the contraflow lanes in Florida (Anderson, 2007). Typically, trucks reduce the number of vehicl es able to travel on the roadway because they require more space, starting dist ance, and stopping distance. These policies were incorporated into the analysis for evaluating the impr oved capacity performance measure. Alternative C1 identifies the use of the shoulder lane for outbound tr avel. However, this additional capacity is minimal when compared to the additional capacity achi eved from Alternative C2 (when Alternative C2 is compared to Alternative C1).
78 However, when the average speed is lowered to obtain a greater throughput, a cross-sectional capacity analysis demonstrates t hat the contraflow lanes may obtain equal throughput as the regular outbound lanes. In summary, Alternative D demonstra ted the greatest average speed for the first part of the capacity analysis and did demonstrate the greatest th roughput for the second part of the analysis. Alternative D experienced an average speed of 61 mph for the equal volume conditions. Alternatively, Alternative A ex perienced the lowest average speed of 35 mph for the equal volume conditions. Each of the other three alternat ives experienced an average speed range between 4357 mph. Tables and graphs summarizing the ca pacity analysis results are provided below. Detailed report printout reports are provided in Appendix A.
79 Table 9 Average Speed Comparison with Constant Volume Alternative Outbound Direction Volume = 6,150 vehicles per hour Normal Outbound Lanes Contraflow Lanes Weighted Average Speed Lanes Volume Ideal Sat. Flow Rate per Lane Total Sat. Flow Avg Speed Lanes Volume Ideal Sat. Flow Rate per Lane Total Sat. Flow Avg Speed A 3 6,150 2,091 6,150 35 -0 -0 -35 B 3 5,077 2,091 6,150 40 1 1,073 1,300 1,300 59 43 C1 3+1 5,181 1,773 6,950 51 1 969 1,300 1,300 61 53 C2 3 3,925 2,091 6,150 56 2 2,225 1,744 3,487 58 57 D 3 3,075 2,091 6,150 61 3 3,075 2,050 6,150 61 61
Co n Total n traflow Ave r Saturation F 0 1 0 2 0 3 0 4 0 5 0 6 0 7 0 Speed (mph) 2 4 6 8 1 0 1 2 1 4 Saturation Flow (vehicles per hour) r a g e Speed C F low vs. Con 0 0 0 0 0 0 0 0 AB Cont r 0 2 ,000 4 ,000 6 ,000 8 ,000 0 ,000 2 ,000 4 ,000 A C 80 Fi g ure 1 7 C omparison s Fi g ure 1 8 traflow Alte r C1C2 r aflow Alterna t BC1 C ontraflow Alt e 7 s Usin g LOS 8 r native for L O D t ive C2D e rnative E Service V o O S E Service Regular Lanes Contraflow La Weighted Av e Reg u Con t Tot a o lumes Volume nes e rage u lar Lanes t raflow Lanes a l Flow Rate
81 The second method of the improved capacity performance measure was based upon identifying which alternative could produce the greatest thr oughput of vehicles, or the greatest volume during a hurricane evacuation. This evaluat ion would identify the greatest density prior to creating excessive congestion where vehicle speeds would be slow. Therefore, the average speed was assumed at approximately 30 mph to evaluate the maximu m throughput for each alternative during an evacuation. In summary, Alternative D demonstra ted the greatest average speed for the first part of the capacity analysis and did demonstrate the greatest thr oughput for the second part of the analysis. Alternative D experienced the greatest throughput of 10,442 vehi cles per hour. Alternatively, Alternative A exper ienced the throughput at 5,208 vehicl es per hour (vph). Each of the other three alternatives experienced a to tal throughput between t he range of 7,083 and 8,846 vph. Tables and graphs summarizing the capacity a nalysis results are provided below. Detailed report printout reports ar e provided in Appendix B. Table 10 Total Throughput Comparison by Alternative Alternative Eastbound Volume per Hour Average Speed 30 mph Free Flow (Regular Outbound)Contraflow Total Volume Lanes VolumeLanes Volume A 3 5,208 -0 5,208 B 3 5,208 1 1,875 7,083 C1 3+1 6,775 1 1,875 8,650 C2 3 5,208 2 3,638 8,846 D 3 5,208 3 5,233 10,442
82 Several iterations were completed for each simulation alternative. Thr ee or four iterati ons of similar, but varying, volumes were run to identify the total average throughput and the average running speed for each alternative. T he average speed between t he different iterations was resulted at a constant speed of approximatel y 30 mph. Provided below is a summary table of the Synchro/SimTraffic simulation modeling results. Al so, provided is a graphical summary of the total throughput comparison summary for each contraflow alternative for a constant speed of 30 mph. Table 11 Simulation Modeling Results fo r Analyzing Total Throughput
Pr o A v e To t To t Av e In id e o vided below e ra g e Speed wi t t al Saturation Fl o t al Throughput e ra g e Scaled S summar y Al t e ntified as th e Note: As s T o is a summar y C u t h Constant Vol u o w Rate S core ( 0-5) t ernative D, w e best alterna t 2,0 0 4,0 0 6,0 0 8,0 0 10,0 0 12,0 0 Volume (vehciles per hour) s umed at a const a o tal Throu g h p y of the scori n u mulative Ev a A lter A u me w hich utilizes t t ive for the im 0 0 0 0 0 0 0 0 0 0 0 0 0 A Co83 a nt speed of 30 m Fi g ure 1 9 p ut vs. Cont r ng s for each m Table 12 a luation of I m native A A lter n B 5 3. 5 4. 5 3. 5 3. he f ull contra f proved capa c BC1 ntraflow Alter n m ph.. 9 r aflow Alter n m easurement m proved Ca p n ative B A ltern C 1 5 1. 5 0 3. 2 2 1. 8 6 2. 2 f low operatio n c it y performa n C2D n ative n ative of improved c p acit y ative 1 A ltern a C 2 5 0. 8 2 2. 2 8 1. 6 2 1. 5 n of the inbou n ce measure. Regul a Contr a Total F c apacit y : a tive 2 A ltern a D 8 0 2 0 6 0 5 0 nd lanes, wa s a r Lanes a flow Lanes F low Rate a tive s
84 Table 13 Improved Capacity Performance Measure Summary Score Alternative 1 D 2 C2 3 C1 4 B 5 A Required Infrastructure This required infrastructure performance measure is based upon materials and infrastructure needed to implement a contraflow operation duri ng hurricane evacuation. The primary type of additional infrastructure is t he orange cones needed to delineate tra ffic from their desired lanes and routes. Other infrastructure includes gates and sign age. The most effective contraflow alternative for this performance measure requires the l east amount of additional infrastructure. The more infrastructure that was required, the mo re increase there would be in the amount of time and human resources needed for activation. In addition the more infrastructure required, the more it would add to the complexity of implementation, and to the likelihood of some thing going wrong that could jeopardize an effective evacuation. It was determined that Alternative D would require approximately 3,000 orange cones to implement contraflow for a distance of 63 miles. (Ander son, 2007) The number of cones required for
85 Alternatives B and C would be much greater bec ause of the need to separ ate outbound traffic from any inbound traffic for the same 63 miles. Also, the maintenance of extra cones for Alternatives B and C would be very high because of travelers dr iving over and knocking over the cones. The recent reconstruction of I-4 to six-lanes of general traffic was recently completed; however, the reconstruction does not permit shoulder riding across bridges. (Anderson, 2007) Therefore, Alternative C1 would be difficult, if not impossible to realisticall y implement. Thus, the required infrastructure to operate Alternat ive C1 would require the reconstr uction of the bridge spans, which would be an extremely costly meas ure. This eliminates the feasib ility of Alternat ive C1 for the purposes of this research. However, for the purpose of this research study, Al ternative C1 was evaluated. For Alternatives B, C1, and C2 cones were assumed to be placed approximatel y every 50 feet. Other equipment may consist of typical costs that are part of an existing infrastructure, such as electronic signage, while other cost s are representative only for contraflow, such as gates to control accessibility between inbound lane s and outbound lanes. Resources necessary to implement contraflow may include the following: Manual gates to provide traffic control at interchange ramps and other entry points Variable Message Signs (VMS) Highway Advisory Radio (HAR) Fold-down signs Dedicated media outlets Typical media outlets Automated Gates
86 The availability of resources and equipment is diffi cult to measure and rely upon during the times of an oncoming hurricane. (Hibbard, 2006) Each storm has its own unique characteristics, and the manner in which the general public reacts to a storm can be unique for each hurricane. For example, the news media may cover a hurricane evacuation in more det ail for the first storm of the season, rather than the tent h storm of the season. More simplistic methods of contraflow are good for dependability and quick implementation. Easy and cost effective strategies are pr eferred. A summary of the cost considerations is provided below: Table 14 Equipment Cost Comparison Equipment Comparative Cost Manual Gates $ Variable Message Signs (VMS) $ (Able to use for other purposes) Highway Advisory Radio (HAR) $ (Able to use for other purposes) Fold Down Signs $ Dedicated Media Outlets $$ Typical Media Outlets $ Automated Gates $$$ Note: The number of $-symbols indicates relative cost. More $ indicates more cost. It is anticipated that different contraflow alte rnatives require different amounts of necessary equipment that would be required to notify the general public and to di rect traffic. Alternative A would require little or no additi onal equipment to operat e under regular operations. After Alternative A, Alternative D is considered to require the least am ount of equipment for operation. This is
87 because the reversal of all inboun d lanes to operate as outbound lanes is a more straight forward operation than Alternatives B and C. More not ification and equipment would be required to effectively separate the dire ction of the inbound lanes. Table 15 Required Number of Orange Cones for Operation Alternative A Alternative B Alternat ive C1 Alternative C2 Alternative D Number of Cones 0 9,650 >10,000 9,650 3,000 Scaled Score (0-5) 0 4.8 5 4.8 1.5 Table 16 Alternative Comparison of Required Equipment Alternative A Alternative B Alternative C1 Alternative C2 Alternative D Equipment Score 1.0 3.0 3.0 3.0 2.0 Georgia uses an automated system fo r gates, which is very expensive This cost would be several times greater in Florida considerin g the length of contraflow is 63 miles for I-4 while distances on other evacuation routes are even longer.
88 A summary of required infrastructure performance measure is provided below. The scorings are compiled between the required number of orange cones and the required equipment. Table 17 Summary of Required Infrastru cture Performance Measure Alternative A Alternative B Alternat ive C1 Alternative C2 Alternative D Cones 0 4.8 5.0 4.8 1.5 Other Equipment 1.0 3.0 3.0 3.0 2.0 Scaled Score (0-5) 0.5 3.9 4.0 3.9 1.75 Required Personnel Similar to the previous required infrastructure, this performance measure of required personnel is based upon the number of safety and law enforcement personnel to effectively implement the contraflow operation. The fewe r number of personnel required for c ontraflow operation, the more favorably it is scored. During the time of a hurricane evacuation, governm ent resources are strained to ensure the public welfare and public safety. Local Emergency Oper ation Centers (EOCs) are running on full
89 activation to coordinate evacuation procedures between the different governmental agencies and media reports. Roadway emergency crews are on fu ll alert to ensure the roadways are operating safely, free from debris, st alled vehicles, etc. The primary personnel to operate a safe and efficient contraflow operation are law enforcement and FDOT personnel. Law enforcement personnel help r egulate the direction of traffic and monitor key intersections and key interchanges o perating through contraflow. FD OT personnel monitor traffic operations through Closed Circuit Television (CCTV) and continuous traffic count stations. Interstate-4 contraflow was most recently desig ned in June, 2006. Con traflow design plans have been updated for the six-laning capac ity improvement. The design plans are considered to be classified documents for security/terrorist reasons. Therefor e, the researcher is not able to incorporate the design plans into the report; how ever, contraflow design plans are updated every year. New plans are incorporating gate locati ons and flip sign locations. (Anderson, 2007) The Florida evacuations for the hurricanes in 2004 and 2005 worked successfully without contraflow lanes. It should be noted that those hurricanes experienced limited evacuat ion, and are not a fair example of how to demonstrate the need for contra flow. Contraflow is considered as the last alternative only when regular oper ations are insufficient as individual drivers will become more aware of other major available r outes besides the interstate. In terstate-4 was designed for 63 miles of contraflow. This design of I-4 contraflow requires more monitoring personnel than any other contraflow plan in the state of Florida. (Hibbard, 2006) This requ irement may be because of I-4 containing the most number of interchanges within an urban envir onment along t he contraflow route.
90 The current I-4 contraflow des ign plan (Alternative D) require s the activation of 105 FDOT personnel. Road rangers are provided on every ev acuation route to assist, not just on the interstate. Approximately 89 r epairmen, 109 trucks, and 53 vans are required to ensure timely arrivals, timely repairs to stalled vehicles, and nec essary towing if the stalled vehicle cannot be fixed. (Anderson, 2007) Figure 20 Alternative D Personnel Requirements Because of the fact that Alter native A operates under regular conditi ons, it is antic ipated that no additional personnel are required for operation. Therefore, since Alte rnative A does not require any additional personnel, it received the best score for th is performance measure. Additional personnel to monitor an evacuation are ex pected when the evacuation order is given; however, they are not required since the amount of capacity is the same as it is for normal operations. 0 20 40 60 80 100 120 PersonnelRepairmanTrucksVansNumber RequiredAlternative D Personnel Requirements
91 As previously stated, Alternativ es B and C require more infrast ructure, mostly because of the additional cones. Additional cones require addi tional manpower for installation and then, subsequently, require more personnel to maintain the cones. Mainline co nditions need to be monitored for delineation so that vehicles do not a ccidentally wander into onc oming traffic. During an evacuation, it can be expected that several vehicles will acci dentally drive over the cones requiring additional personnel to replace the cones. It can be expected that Alternative C1 requires t he most number of personnel because of using the shoulder lane for additional capacity. The ability to maintain a free flow operation of the shoulder lane (instead of being used for stalled vehicles) is essential. A stalled vehicle stored on the shoulder lane would elim inate the additional c apacity and actually create an upstream bottleneck due to vehicles attempting to merge over. Ther efore, additional personnel would be required to quickly remove the stalled vehicles, in addition to those personnel required to monitor the utilization of cones on the contraflow lane. Alternatives B and C2 require the same amount of additional personnel That is because the same number of cones would be utilized to create one contraflow lane as would be necessary to create two contraflow lanes.
92 Table 18 Summary of Required Personnel Performance Measure Alternative A Alternative B Alternat ive C1 Alternative C2 Alternative D Scaled Score (0-5) 0.0 3.5 4.0 3.5 2.5
93 Speed Variation Speed variation is considered a performance measur e primarily because of safety issues. The more variation in speed during an evacuation the more likelihood there is of a safety risk, mostly because of side swiping and/or rear end collisions. The concern is magnified during an evacuation because the roadway is operating at capacity. When a crash occurs, the resulting congestion delay has much greater significance during a ti me when throughput is most important. Therefore, this performance measur e is rewarded by the consistency or the lack of speed variation. Synchro/SimTraffic was used to evaluate the speed variation. The difference of speed between the contraflow lanes and the regular outbound lanes was considered. Drivers may become distracted when they see other vehicles on the other lane group traveling the same direction at a different speed. This may espec ially be distracting for dr ivers that see the other lane group traveling faster and wanting to fi nd ways to travel faster themselves. Anxiety is elevated for drivers during an evacuat ion because of the need to travel long distances and the need to arrive at the secu re destination prior to the hurri cane making landfall. Noticing a different lane group moving faster during congestion may add to drivers anxiety in the slower lane group and ultimately increase the frequency of risk maneuvers by drivers desiring to speed ahead. Risks, such as traveling on emergency lanes, sh oulders, and in opposite travel lanes were documented during the Hurricane Ri ta evacuation. This incr ease in risk maneuvers and speed variation eventually leads to additional safety risks.
94 Figure 21 Average Speed Variation Between Re gular Lanes and Contraflow Lanes 0 2 4 6 8 10 12 14 16 18 20 Alternative AAlternative BAlternative C1Alternative C2Alternative DAverage Speed Variation between Regular Lanes and Contraflow Lanes(mph)
95 Table 19 Summary of Speed Variat ion Performance Measure Alternative A Alternative B Alternat ive C1 Alternative C2 Alternative D Scaled Score (0-5) 0.0 5.0 2.6 0.5 0.0 The speed variation was measured up on using a consistent of LOS E generalized service volume of 6,150 vehicles per hour. It was identified that the contraflow lanes generally travelled at a faster speed than the regular lanes. This is because fe wer vehicles are anticipated to travel on the contraflow lanes. The only alternative where the contraflow lanes traveled slower than the regular lanes was Alternative D. Additionally, the speed variation was evaluated fo r each lane group. However, only the outbound evacuation direction was evaluated for speed variation (not the inbound direction). It was identified that Alternative C1 contained the greatest speed variation. This is mostly because of C1 utilizing the shoulder lanes. This is because the shoulder la nes are expected to trav el slower than other mainline outbound lanes as the shoulder lane will create a side friction factor causing reduced speeds. This is primarily because of the shoulder lanes are designed to be 10 feet wide, as opposed to the regular travel lanes having a widt h of 12 feet. Also, the shoulder lanes have inferior pavement and
96 debris, which can disrupt free flow speed. Shoulder lanes typically also have rumble strips, which can disrupt drivers by the induced noise and, as a result, create a safety concern. Drivers unfamiliar with driving in the opposite di rection may lead to greater speed variation. Different drivers may travel slower on the cont raflow lanes. The corresponding free flow speed on the contraflow lanes would wi tness more variation depending on driver roadway and driver characteristics. Drivers in the contraflow lanes ar e likely traveling under those conditions for the first time. They would experience typical signage in the opposite direction, a reverse median, and interchange lane assignments in the opposite direct ion. If cones are knocked over during the evacuation (such as Alternative B, C1, and C2), this situation would re sult in greater speed variation, adding to a great er safety concern. Speed variation is one of the ma jor contributing factors to cras hes on grade separated highways. Previous research has demonstr ated that crash frequency significant ly increases when drivers are unsure of the safe driving speed for diffe rent driving conditions. (Collins, 2000) Logistics The logistics performance measure is determined by how much required set up time and the set of circumstances there is to potentia lly implement contraflow. Also, the logistics performance measure incorporates the amount of effort r equired to convert the contraflow l anes back to regular operation. This performance measure is different than the other performance measures because it measures the effort required establishing each alternativ e, as opposed to the other performance measures
97 which only evaluate the benefit of each alter native upon set up. The am ount of cooperation and time for set up is a key component of this performance measurement. When this dissertation began, the deployment of th e National Guard was part of the evacuation policy to establish and manage contraflow oper ation. The National Guard would require approximately 96-104 hours to fully deploy at the contra flow route, specifically I-4. This time sequence of three to four days would have been prohibitive during an onc oming hurricane. The purpose for deploying the National Guard would be primarily to m anage traffic control at crossing locations and interchanges and to securely monitor evacuation. By the time the National Guar d would have been fully deployed, the ability to effectively evacuate the general population would have passed. During the time period while this dissertation was performed, the policy to deploy the National G uard was removed. Their responsibility was delegated to local and state law enforce ment, and FDOT personnel, who c ould effectively deploy on scene much quickly and efficiently. The updated hurricane evacuation plan now identifies a full contraflow (Alternative D) in much less time without the National Guard. Alternative D is currently identified for a six (6) hour set up before contraflow operations and a four (4) hour breakdown after contraflow operations. A handout describing how Alternative D may operate is provided below.
98 Figure 22 FDOT Contraflow Logistical Handout Since Alternative A operates under regular operations, Alternative A would require less logistical coordination than the other alter natives during an evacuation. For this performance measure, Alternative A is logically considered the best Al ternative for the easiest logistical operations. An evaluation was undertaken to consider the time line of events and circ umstances likely required to determine the need for contraflow operation, impl ement contraflow, and to resume back to normal operations. The process begins with the developi ng hurricane in the open sea. The storm event is then forecasted upon a projected route with an antic ipated landfall location. When a storm event transforms from a tropical storm to a hurric ane the local Emergency O peration Center (EOC)
99 becomes activated for the counties affected near t he projected landfall loca tion. (Anderson, 2007) The following graphic summarizes the proce ss of events to implement contraflow. Figure 23 Conceptual Time Line of Even ts to Implement Contraflow The next step in the process is the evacuation orde r, followed by the monitoring of traffic volumes on the evacuation route (which in this dissertati on is I-4 in Central Florida). Permanent traffic counters installed into the highway pavement and CCTV provide continuous traffic count data and visual for monitoring congestion le vels. One of the special considerations with contraflow is determining what level of congestion is requir ed to warrant contraflow, and when the decision should be made. As approximately six hours is needed to implement contraflow, that means 24681012141618202224 Forecast storm path Developing hurricane Evacuation order Monitor Growing Traffic Volumes (variable length of time) Notify Governor approval to im p lement Stage personnel and equipment Clear WB traffic Implement all lanes EB flow Shutdown Resume normal operation Hour Decision point to implement Activate EOC
100 whenever the decision is made to implement contrafl ow, congestion is likely to keep building for the six hours until contraflow becomes operational. Th erefore, the ability to anticipate the need for contraflow six hours before it is needed may greatly allevi ate congestion during an evacuation. This aspect alone may justify a topic of future study. When traffic volumes exceed acceptable congestion, the order to implement is then given from the Governors office following a local request. The process to stage the personnel and equipment, and then to clear the westbound (inbound) traffic, is under taken to implement contraflow for all outbound lanes. The contraflow is activated for the nece ssary period of time until the evacuees are served and traffic volumes decline. Then, following the evacuation, the next step in the process is to shutdown the operation and then re sume back to normal operations. Certain circumstances are anticip ated around the hurricane event to potentially warrant contraflow implementation. The first circumst ance is that the hurricane would be a Category 4 or 5 storm. As described in previous sections, other states t hat have hurricane plans have a policy to implement contraflow only for a Category 4 or 5. Although this is not offici al policy in Florida, it may be assumed during an evacuation. The next circumstance may be that th e hurricane is that the hurricane is traveling quickly toward the coast, perhaps at 25-35 mph. The fast moving hurri cane likely results in a evacuation where many evacuees depart in a short amount of time, which woul d result in many evacue es arriving to travel on the highway in a relatively sh ort amount of time. This circum stance would resu lt in greater congestion, which may warrant contraflow evacuation.
101 Thirdly, prior to contraflow being implemented, a review of the time of day when congestion arrives to warrant contraflow would be undertaken. The st ate of Georgia and the stat e of Florida currently have a policy not to operate contraflow during nightti me hours. This is because specific safety concerns arise with contraflow operated in the dark, as discussed in previous sections. If congestion reaches levels to warr ant contraflow during evening hour s or late in t he afternoon, the decision to implement contraflow may still not be made. With six hours needed to implement contraflow, the decision may need to be made in t he morning, or the early afternoon hours of the day. Alternatives with partial contra flow implementation, Alternativ es B, C1, and C2 require more logistical coordination. Set up ti me and cost would be increased for these alternatives that require cones along a typical cross section. For I-4, that typical cross sect ion is a distance of 63 miles. These alternatives also require constant maint enance and monitoring. Thes e considerations make Alternatives B, C1, and C2 less successful fo r the logistical performance measure. The amount of time to logistically operate Alternative C1 and C2 is greater than for Alternative A and Alternative D. The number of people needed to deploy is also great er. Approximately nine (9) hours may be needed to deploy Alte rnative C1 and eight (8) hours to deploy C2. (Engerski, 2007) Alternative C1 may require more time because of the need to ensu re that the s houlder lane is cleared for travel.
102 Figure 24 Summary of Set Up and Breakdown Time The amount of set up and breakdown time is considered o ne of the most straight forward measurements of logistics. This is because it assumes the coordination of evacuation personnel and logistics needed to prepare for each contraflow alternative. Ot her logistical considerations, such as operating Highway Advisory Radio (H AR), Variable Message Signs (VMS), road rangers, etc. are expected to be relatively constant among each alternative. In summary, Alternative A is considered the easiest logistically (primarily because it operates under normal conditions). For the cont raflow alternatives, Alternative D is considered to be the most straightforward to implement. Alte rnatives B, C1, and C2 are consider ed to be relatively similar. 0 2 4 6 8 10 12 14 16 Hours Set Up Time (Hours) Breakdown Time (Hours) Total
103 Table 20 Summary of Logistics Performance Measure Alternative A Alternative B Alternat ive C1 Alternative C2 Alternative D Set Up Time 0 8 hours 9 hours 8 hours 6 hours Break Down Time 0 6 hours 6 hours 6 hours 4 hours Total 0 14 hours 15 hours 14 hours 10 hours Scaled Score (0-5) 0.0 4.7 5.0 4.7 3.3 Delay/Congestion The Delay/Congestion performance m easure evaluates the traffic operat ion effects of the different contraflow alternatives. The delay and congestion are a result of how traffic is able to respond to the roadway capacity. It is measured in terms of seconds (or minutes) of delay between each contraflow alternative. The Delay/Congestion performance meas ure has an inverse relationship to the Additional Capacity performance measure. At the onset of evaluation, it was assumed t he alternative that resulted with
104 the most amount of capacity would also result in the least amount of delay/congestion. The alternative with the least amount of delay or congesti on is considered to be the best alternative. Average delay was measured using a total consta nt volume of 6,150 vehicles per hour on the facility. The delay was measured as a total weighted average of volume between the regular outbound lanes and the contraflow lanes. Table 21 and Figure 24 illustrate the results of the analysis. Table 21 Average Delay Comparison with Constant Total Volume Scenario Outbound (Eastbound) Average Delay Per Vehicle with Constant Volume Regular Outbound Lanes Contraflow Lanes Weighted Average Delay (s/veh) Lanes Volume Delay (s/veh) Lanes VolumeDelay (s/veh) A 3 6,150 619.8 --0.0 619.8 B 3 5,077 121.9 1 1,073 24.4 104.9 C1 3+1 5,181 52.1 1 969 16.5 46.5 C2 3 3,925 34.4 2 2,225 23.9 30.6 D 3 3,075 19.3 3 3,075 19.0 19.2
In pe sp e re d A l t de 61 summar y Al t r vehicle. A l e ed. Each d ucin g dela y t ernative A, monstrated a 9.8 seconds. 1 2 3 4 5 6 7 Delay (sec/veh)Avera ge t ernative D d l ternative D h alternative t The compar a which oper a a si g nificant i n Table 22 s u 0 1 00 2 00 3 00 4 00 5 00 6 00 7 00 A C o e Dela y Com p emonstrated h ad an avera hat used co a tive dela y b e a tes under r e n crease of d e u mmarizes th e BC1 o ntraflow Alte r 105 Fi g ure 2 5 p arison with the best res u g e dela y of 1 ntraflow de m e tween Altern eg ular condi t e la y The av e e results of th e C2D r native 5 Constant T o u lts with the l o 1 9.2 second s m onstrated si g atives C1, C 2 t ions and d o e ra g e dela y p e Dela y /Con g Re g Co n We i o tal Volume o west amou n s per vehicle g nificant im p 2 and D wer e o es not imp l p er vehicle fo r g estion perfor g ular Lanes n traflow Lanes i ghted Average n t of avera g e from the fre e p rovements t o e relativel y si m l ement contr a r Alternative A mance meas u dela y e flow o ward m ilar. a flow, A was u re.
106 Table 22 Summary of Delay/Conges tion Performance Measure Alternative A Alternative B Alternative C1 Alternative C2 Alternative D Delay/Congestion (sec/vehicle) 618.9 104.9 46.5 30.6 19.2 Scaled Score (0-5) 5.0 0.9 0.4 0.25 0
107 SUMMARY/CONCLUSIONS The Florida evacuations for the hurricanes in 2004 and 2005 worked successfully without contraflow lanes. As of 2007, contraflow has never been implemented on a grade se parated highway in Florida. Several factors contribute to this. One factor is that Floridas topography is unique with two coastal regions. Also, Florida has generally mo re than one evacuation rout e. For example, the Tampa Bay region may use I-75, I-4, or the Suncoast Parkway to evac uate in the north direction. Contraflow is considered to be an effort of last re sort. Currently, real ti me traffic monitoring has been considered effective via CCTV an d via continuous traffic count stations that were used in previous evacuations. Thus far, evacuations fr om West Central and Sout hwest Florida have not created enough congestion to necessitate contraflow There are several reasons for this. For example, it has been reported that fewer people in re cent history are evacuating longer distances. Also, it has been reported that people are becoming more knowle dgeable of alternate evacuation routes besides the interstate. Alternative D, which is the alte rnative that operates with full contraflow implementation, was determined to be most effective. This conclusi on was based primarily upon the influence of the improved capacity and the delay/congestion perform ance measures. If contraflow is to be implemented, Alternative D is considered the best.
108 Alternative D was scored best, but only by a narrow margin above Alternative A. Alternative A scored the best in the performance measures related to the implement ation and safety. The fewest number of resources are required for Alternative A, resources that ar e strained during the time of an evacuation. The Alternative A scored bes t in the following performance measures: Required personnel Required infrastructure Speed Variation Logistics Each performance measure was evaluated using a weighted scoring system. The alternative with the lowest score was considered the best alternat ive. Alternative D was considered the best alternative with an average score of 1.3. In summary, the conclusi on can be made that the improved traffic operations of contraflow na rrowly provide more benefit than that negative investment required to implem ent contraflow. Table 23 summarizes the results of each performance measure for each contraflow alternative.
109 Table 23 Summary of Performance Measure Evaluation Contraflow Alternative A Normal Operation B Normal Outbound +1 Contraflow C1 Normal Outbound +1 Shoulder +1 Contraflow C2 Normal Outbound +2 Contraflow D Normal Outbound +Complete Contraflow Improved Capacity 5.0 3.6 2.2 1.5 0 Required Infrastructure 0.5 3.9 4.0 3.9 1.75 Required Personnel 0 3.5 4.0 3.5 2.5 Speed Variation 0 5.0 2.6 0.5 0 Logistics 0 4.7 5.0 4.7 3.3 Delay/Congestion 5.0 0.9 0.4 0.25 0 Average Score 1.75 3.6 3.0 2.4 1.3 Note: Lowest scored alternative is considered the best alternative. In the event that congestion amounts to a level t hat unsatisfactorily serves traffic during an evacuation, and contraflow is ultimately requir ed, then it is suggested that Alternative D is implemented. This alternative uses all of t he regular inbound lanes duri ng an evacuation as an outbound lane. Alternative D demons trated to provide the most im proved capacity, while also demonstrating to be the most imple mentable contraflow alternative. If contraflow is implemented, this alternative was demonstrated to be the most efficient, requiring the fewest amount of personnel and resources, while also being the most effective. This is primarily because of removing the deployment of the National Guard during evacuation. The remova l of this requirement took place
110 during the same time period that this research was undertaken. Alternative A was scored second behind Alternative D for required in frastructure, required personnel, and logistics. The average scoring of all the performance meas ures for Alternative A was 1.75. The contraflow alternative with the worst score wa s alternative B. The average score for Alternative B was 3.6. This alternative was scored in t he bottom half of each performance measure. This occurred because Alternative B dem onstrated the greatest speed vari ation. Much of this poor performance was caused by the amount of additional infrastructure t hat would need to be installed, and the number of personnel needed to monitor the o peration for the lanes to be properly and safely delineated within the norma l inbound lane group. So what suggestions should be made from the results and obser vations derived from this dissertation? It is suggested to reduce the significant investment that has been made with regard to contraflow. The need to implement contraflow appears unlikely on I-4 when considering the investment required along with the other mentioned disadvantages, and should only be considered as a last resort. However, it is always chall enging to predict the future when considering the dynamic socioeconomic and changing in frastructure within Florida. Therefore, it should be stressed that these suggestions are provided for the present existing condition s. More importantly, there are other alternatives for reduci ng the need of contraflow that should be considered. One alternative is to increase awareness of other evacuation routes besides the interstate. At times, the other local surface routes, such as U.S. 92 in Hillsborough Count y, are parallel to the interstate evacuation route. During periods of congestion, these local su rface routes may more quickly serve the evacuating public.
111 Observations and Uncertainties This dissertation, to evaluate performance measur es identified the different aspects that should be considered for contraflow. The performance measur es were selected for the purposes of identifying the traffic operational impacts, as well as the personnel, infrastructure, and logistical requirements. It was observed that the traffic operations of c apacity, speed variation, and delay/congestion were more easily to quantify. Conversely, it was al so learned that the other performance measures represented a greater challenge to comparatively evaluate. The performance measures of required personnel, in frastructure, and logistical requirements were more challenging to quantify. The ability to com pare the value of additional personnel is difficult. How should one perform a benefi t/cost analysis of paying law enfor cement personnel overtime pay if they are a significant factor towards an effect ive evacuation? However, the type of measurement undertaken still is reflective of how important t hese factors are and how they may comparatively differ between alternative cont raflow strategies. One challenge was to determine if certain performance measures were more important than others. This dissertation initially assumed that each per formance measure was wei ghted equally. However, a separate evaluation was undertake n that provides more weight to the traffic operational performance measures, and is discu ssed in the next section.
112 There are several uncertainties attr ibuted toward evaluating the potenti al effectiveness. Most of the uncertainties are attributed towards the trav el demand and anticipated tra ffic volumes during an evacuation, such as: Size, development, and intensity of hurricane Speed and direction of hurricane Arrival time of hurricane o Beginning or end of season o Time of day o Day of week Percentage of people that evacuate o Shadow evacuations o Amount of manufactured homes Distance of evacuation Because of these uncertainties, it was observ ed than an evaluation based upon the supply, or capacity, represented a more straightforward approach. This would help determine how many evacuees could be adequately served during an evacuation. As stated above, the majority of uncertainties fo r hurricane and evacuation planning is related to the travel demand aspects onto the transportation infras tructure. Each hurricane event is, and will be, unique. Therefore, the greatest uncertainty is the challenge to prepare hurricane evacuation plans that depend upon previous events.
113 Alternative Method of Weighting Performance Measures The initial evaluation assumed that each perfo rmance measure contained the same amount of influence towards evaluating the overall effectivene ss. However, one may successfully debate that the ability to provide e nough capacity for evacuees may be of mo re importance than the investment of additional personnel and tem porary infrastructure. The Delay/Congestion performance m easure was developed later duri ng the research process to more effectively account for the importance of providing adequate service. The Improved Capacity performance measure and the Delay/Congestion perfo rmance measure are similar in determining effective service with their inverse relationship. Therefore, an effort was underta ken to consider how each of t he different performance measures may be weighted differently. Initially, the abilit y to weigh the differences may be considered somewhat of a subjective evaluation. However, this effort to weigh the performance measures was a result of several methods of input and research. Interviews were conducted with Florida DOT st aff regarding which perform ance measures were considered more important. FDOT staff provided impa ct that it is inherently difficult to measure the cost/benefit difference between the benefit of safely evacuating the general public versus the cost of paying overtime personnel costs (Anderson, 2007) It was inherently det ermined that improved capacity and the reduction of delay/congestion wi th contraflow would be at least double the importance of the required infras tructure of orange cones (especially when considering that the
114 orange cones are not required for Alte rnative D). More so, the ben efit of reduced delay/congestion was considered to be slightly more important than improved capacity. That is because the delay/congestion is a resulting performance m easure, and the results may be considered to be more important than the contributing factors. Similar discussions were undertaken with st aff from the Tampa Bay Regional Planning Council regarding the importance to weigh t he different performance measures. Similarly, it was determined that delay/congestion was considered to be the most important performance measure. In addition to interviews literature reviews were undertaken for evaluating the performance measure weighting system. Previous reports published by the Texas Department of Highway Safety identified the importance of efficient logistics, and how per sonnel requirements and infrastructure requirements may change over time to create a more efficient process (Galvin, 2002). Speed variation between the contraflow lanes and the r egular outbound lanes was previously identified to not be as significant of a contributable fa ctor towards a successful evacuation. Each performance measure was then listed by order of priority as a result of the conducted interviews and literature review. It was deter mined the weighting of t he performance measures would be provided in the following priority: Delay/Congestion Improved Capacity Logistics (tie) Required Personnel (tie) Speed Variation Required Infrastructure
115 The weighting of each performanc e measure was considered agains t the baseline of the lowest weighted performance measure of R equired Infrastructure, weighted at 1.0. The Delay/Congestion performance measure was considered to be of the greatest importance wi th a scaled weight of 2.25. This is because delay and congestion are probably t he most significant factors that can inhibit a successful evacuation. Following the Delay/C ongestion performance meas ure was the Improved Capacity performance measure with a scaled weight of 2.0. The performance measure with the lowest scaled weight was Requir ed Infrastructure. This is because the primary measure of add itional infrastructure consiste d of the additi onal orange cones needed to delineate traffic. This does not directly influence the perfor mance of an evacuation, but is merely a measurement of one component of in vestment to help supply the contraflow. An alternative method of weight ing the performance measures wa s introduced to provide more significance of evacuation capacity. The process of eval uation was similar, but for this alternative analysis, each of the different performance m easures was assigned an assumed weight of significance. Provided below is a summary of t he evaluation results using the alte rnative weighting method. The performance measures related to capacity and se rving the evacuation public were provided a greater weight.
116 Table 24 Summary Matrix Using Weighted Scaling Alternative Contraflow Alternative Scaled Weight A Normal Operation B Normal Outbound +1 Contraflow C1 Normal Outbound +1 Shoulder +1 Contraflow C2 Normal Outbound +2 Contraflow D Normal Outbound +Complete Contraflow Improved Capacity 2.0 10.0 7.2 4.4 3.0 0 Required Infrastructure 1.0 0.5 3.9 4.0 3.9 1.75 Required Personnel 1.5 0 5.25 6.0 5.25 3.75 Speed Variation 1.25 0 6.25 3.25 0.6 0 Logistics 1.5 0 7.05 7.5 7.05 4.95 Delay/Congestion 2.25 11.25 2.0 0.9 0.6 0 Average Score n/a 3.6 5.3 4.3 3.4 1.7 In summary, after applying the sca led weights, the performance me asures of improved capacity and delay/congestion benefited greatly. The contraflow alternative that benefit ed the most from the scaled weighting of those two per formance measures was Alternativ e D (Complete Contraflow). The results of the scaled weig hted performance measures demons trated a greater differential between Alternative D and Alternative A. Alternative C2 benefitted wi th the scaled weighting, and scored second, while Alternative A was scored lower as the third best alternative.
117 In summary, both the scaled wei ghted analysis and t he original analysis demonstrated one major observation; that if contraflow is implemented, a full contraflow ha s consistently more benefit than the partial contraflow alternatives, and a slight ly greater benefit than normal operations during a hurricane evacuation. Future Research This research has been directed towards evaluati ng the hurricane evacuation of I-4 in the West Central Florida region; however, many aspects of the research apply to wherever hurricane evacuation occurs. Some aspects of contraflow al so relate to the evacuation of the general public. The United States still uses mass evacuation as the predominant method of safely preparing for a hurricane. However, recent evacuation surveys hav e demonstrated that many people are starting to modify their plans for evacuation. Recent trends have shown more local evacuations within the same regi on and using alternate routes besides the interstate. Additionally, the pub lic is becoming more info rmed of real time traffic conditions to monitor their evacuat ion routes and plan for their evac uation accordingly. This may become a topic to consider for future research. Ultimately, the combinati on of continual population increase in Florida growing faster than the rate of typical road way capacity will necessitate the increasing efficiency of the existing transportation infrastructure to safely serve the evacuating public.
118 This dissertation can be applied to: Other types of evacuation planning and modeling o Floods o Fires o Manmade disasters Operation planning of potential reverse lane fac ilities with significant peak hour directionality While this dissertation can be applied to several di fferent types of mass evacuations, such as floods, fires, or manmade disasters, each type of evac uation planning should c onsider the following: Shape and size of energy source Shape and size of evacuation area Rate of growth of evacuation area Size and socioeconomic data of evacuation population Amount of warning time Level of disruption to the road network Level of danger of the emergency The side-by-side analysis of diffe rent laneage configurat ions and alternatives presented in this dissertation can be used as a framework toward futu re research. The real ity of travel demand uncertainties is addressed in this research and may be referenced for future st udy. Future research can also reference the constantly changing behavioral tendencies of evacuees. It is suggested that future research focus on t hese behavioral trends. So mething new is learned after each hurricane. Future research may addre ss the changing characteristics of evacuees. One characteristic of evacuees that may be re searched is the route assignment. Are evacuees dependent upon using only interstate and grade sepa rated highways for evacuation, or are other
119 parallel local facilities determined to be as beneficial? Would the advertisement of other parallel facilities be an effective method of avoiding the need of contraflow? Future research may also address the relations hip between hurricane evacuation zones and land elevation. It has been docum ented that the majority of hur ricane damage and human deaths is caused from inland flooding, not coastal flooding or wind damage. Therefore, the identification of damage-prone locations and hurricane evacuation zone s should extend beyond coastal locations. The ability to anticipate the need for contraflow prior to congestion may also be a topic of future research. Currently, 6-8 hours is anticipated to be needed to implement contraflow. Therefore, the ability to predict the need for c ontraflow approximately 6-8 hours in advance would further facilitate successful hurricane evacuations.
120 REFERENCES 1. Federal Highway Administration, Transpor tation Evacuation Planning and Operations Workshop, 2005 National Hurricane Conference, http://ops.fhwa.dot.gov accessed March 2006. 2. Wolshon, Brian; Urbina, Elba and Levitan, Marc National Review of Hurricane Evacuation Plans and Policies, Louisiana State University Hurricane Center, 2001. 3. Barret, Bridget; Ran, Bin and Pillai, Rekha, Developing A Dynamic Traffic Management Modeling Framework for Hurricane Evacuation, Transportation Research Board, Paper No. 00-1595, January 2000. 4. Virginia DOT, Hampton Roads Hurricane Traffic Control Plan, Revised July 2001. 5. Galvan, John and Hamilton, Joseph, Traffic Management & IH 37 Conversion Plan, Texas Department of Public Safety, Highway Patrol Service District 3A and 3B, June 2002. 6. NOAA, Hurricane and Impact Assessment Reports, www.csc.noaa.gov accessed February 2006. 7. USACE, FEMA, and NOAA, Informati on on Hurricane Evacuation Studies, www.saw.usace.army.mil accessed February 2006. 8. PBS&J, Hurricane Andrew Assessment-Florida, prepared for US Army Corps of Engineers and FEMA, January 1993. 9. PBS&J, Hurricane Isabel Assessment, prepar ed for US Army Corps of Engineers and FEMA, March 2005. 10. Anderson, Ron and Engerski, Jeff, Florida DOT District Seven, personal interview, April 2006 and June 8, 2007. 11. PBS&J, Tampa Bay Hurricane Evacuation Study Update 1999, prepared for Tampa Bay Regional Planning Council, March 2000. 12. PBS&J, 2006 Tampa Bay Hurricane Evacuation St udy Update, prepared for the Tampa Bay Regional Planning Council, 2006.
121 13. Hibbard, John, Best Contraflow Practices, presented at the Trans Po 2006 Annual Meeting sponsored by Florida Section IT E, Palm Harbor, Florida. 14. Yik Lim, Yu, Modeling and Evaluating Evacuat ion Contraflow Termination Point Designs, Louisiana State University, August 2003. 15. Collins, Jason, Evaluation of a Real-Tim e Traffic Warning System for Wet Pavement Conditions, University of Sout h Florida Masters Thesis, 2000. 16. Wolshon B., Urbina E.,and Levit an M.(2002). "National Review of Hurricane Evacuation Plans and Policies" LSU Hurricane Center, Louisiana State Universi ty, Baton Rouge, Louisiana. 17. Wolshon, B., (2001). "One-Way-Out: Contra flow Freeway Operation for Hurricane Evacuation." Natural Hazards Review, Vol. 2, No. 3, pp. 105-112. 18. Wolshon, Brian and Catarella-Michel, Alis on, Louisiana Highway Evacuation Plan for Hurricane Katrina: Proactive Management of a Regional Evacuation, Journal of Transportation Engineering Vol. 132 No. 1, American Societ y of Civil Engineers, 0733947X. 19. Wolshon, Brian, Brotherly Advice: Learning from Hurricanes Georges and Ivan, Louisiana avoids Katrina Massacre, Roads & Bri dges Vol. 44 No. 3, Scranton Gillette Communications, Incorporated, ISSN: 8750-9229. 20. Lawley Publications, Texas to develop contra flow plans for hurricane evacuation routes, Urban Transportation Monitor Vol. 20 No. 6, Mar. 31, 2006. 21. Williams, Billy M, Tagliaferri, Anthony P, Meinhold, Stephen S, and Hummer, Joseph E, Simulation and Analysis of Freeway Lane Reve rsal for Coastal Hurricane Evacuation, Journal of Urban Planning and Developm ent Vol. 133 No. 1, ISSN: 0733-9488. 22. Ballard, Andrew J, Traffic Operations fo r Hurricane Evacuation, Transportation Research Board 86th Annual Meeting, Date Held: 20070121 20070125. 23. Ballard, Andrew J, and Borchardt, Darr ell W, Recommended Practices for Hurricane Evacuation Traffic Operations, Texas Trans portation Institute, Accession #01029067, 2006. 24. Wilmont, Chester, Wolshon, Brian, Hamilton, and Urbina, Elba, Revi ew of Policies and Practices for Hurricane Evacuation. II: Traffic Operations, Management, and Control, Natural Hazards Review Vol. 6 No. 3, Amer ican Society of Civil Engineers, ISSN: 15276988.
122 25. Wolshon, B, "One-Way-Out": Contraflow Free way Operation for Hurricane Evacuation, Natural Hazards Review Vol. 2 No. 3, Amer ican Society of Civil Engineers, ISSN: 15276988. 26. Lim, Erick, and Wolshon, Brian, Modeling an d Performance Assessm ent of Contraflow Evacuation Termination Points, Transporta tion Research Record: Journal of the Transportation Research Board No. 1922, Transportation Rese arch Board, ISSN: 03611981.
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ABOUT THE AUTHOR Jason Scott Collins, Ph.D, P.E., AICP was orig inally born and raised in Milwaukee, Wisconsin. Building from his persona l hobbies of geography and automobiles, he att ended Vanderbilt University where he obtained is Bachelor of Engineering degree with a focus on transportation. Then shortly after, Jason attended University of South Florid a where he received his Ma sters degree in Civil Engineering through the Universitys Interdisci plinary Program of Pub lic Administration and Economics. Transforming his personal hobbies into his care er, Jason has since worked for consulting engineering firms managing transpor tation planning, traffic operat ions, permitting, and design projects. He is currently the Florida Manager of Trans Associates Engineering Consultants, Inc. Jason lives in Tampa, Florida with his wife Carly.
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Evaluation of contraflow lanes for hurricane evacuation
h [electronic resource] /
by Jason Collins.
[Tampa, Fla] :
b University of South Florida,
Title from PDF of title page.
Document formatted into pages; contains 249 pages.
Dissertation (Ph.D.)--University of South Florida, 2008.
Includes bibliographical references.
Text (Electronic dissertation) in PDF format.
ABSTRACT: This dissertation evaluates contraflow during a hurricane evacuation for grade separated highways. Contraflow is the concept of reversing the typical direction of highway travel to provide more outbound roadway capacity. The State of Florida has spent more time and resources towards the planning and the designing of potential contraflow facilities than any other state in the country; however, contraflow has yet to be implemented (as of Summer 2008). This study determines if the additional capacity benefits of contraflow outweigh the logistical requirements of implementing contraflow. Five different alternatives of contraflow lane configurations were comparatively evaluated. The format of this study is unique due to the evaluation of both capacity and logistical measurements. Each alternative was subject to evaluation of six different performance measures.The six different performance measures consisted of improved capacity, speed variation, logistics, required personnel, required infrastructure, and delay/congestion. Each performance measure was evaluated using a scaled scoring system. The alternative with the lowest average scoring among the different performance measures was considered the best alternative. Contraflow should only be considered as a last resort. The loss of inbound access, safety concerns,logistical requirements, and the additional strain of public resources during an evacuation are negative aspects that should be considered when determining the capacity benefit. If extenuating circumstances justify contraflow, then a full conversion of all inbound lanes to outbound lanes, known as Alternative D, should be considered. This alternative demonstrated the greatest capacity benefit while requiring the least amount of public resources.However, instead of contraflow, it is suggested to divert public resources towards other, more practical alternatives. Real time traffic monitoring has been demonstrated to be quite useful. Publicly accessed web-pages on the internet and the recent installation of variable message signs all provide improved notification of traffic conditions and of the capability to use alternative "atgrade" evacuation routes in addition to using the grade separated highways. This driver notification and the ability to ensure the safe and efficient travel on these alternative routes may be worth further investment, as well as being a potential topic of future research.
Mode of access: World Wide Web.
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Advisor: Jian Lu, Ph.D.
x Civil and Environmental Engineering
t USF Electronic Theses and Dissertations.