Evacuation Traffic Dynamics and Development of Maximum Sustainable Evacuation Traffic Flow Rates

Traffic simulations are being increasingly applied to study evacuation operations. These studies utilize capacities from the Highway Capacity Manual or those observed during regular non-emergency conditions. This paper introduces two main concepts the Maximum Evacuation Flow Rate (MEFR) and the Maximum Sustainable Evacuation Flow Rate (MSEFR). MEFR should be used to calibrate simulation models that model the network extensively, while the MSEFR which were found to be a result of downstream bottlenecks should be used as a measure of capacity while looking at single corridors or small networks. This study utilizes data collected during Hurricanes Ivan 2004, Katrina 2005 and Gustav 2008 to compare evacuation operations with those observed during a regular non-emergency peak. A 10 percent reduction in capacity from regular non-emergency peak was observed during an evacuation for MEFR in non-urban areas, while larger reductions of approximately 15 percent were found in urban areas. A 30 percent drop in capacity from regular non-emergency peak was observed for the MEFR during contraflow operations. MSEFR of 600 veh/hr/lane were observed during non-contraflow conditions and 800-1000 veh/hr/lane were observed during contraflow conditions. The free flow speeds during evacuation were found to be significantly higher than those observed during a regular non-emergency peak. Systematic differences were also observed during contralfow and non-contraflow conditions.

• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Dixit, Vinayak V
  • Wolshon, Brian
  • 0000-0002-1703-2995
  • Montz, Thomas
• Conference:
  • Transportation Research Board 90th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2011-1-23 to 2011-1-27
• Date: 2011

Language

• English

Media Info

• Media Type: DVD
• Features: Figures; References; Tables;
• Pagination: 18p
• Monograph Title: TRB 90th Annual Meeting Compendium of Papers DVD

Subject/Index Terms

• TRT Terms: Bottlenecks; Contraflow lanes; Disasters and emergency operations; Evacuation; Free flow speeds; Highway capacity; Hurricanes; Network analysis (Planning); Traffic flow rate; Traffic simulation
• Subject Areas: Data and Information Technology; Highways; Operations and Traffic Management; Security and Emergencies; I71: Traffic Theory; I73: Traffic Control;

Filing Info

• Accession Number: 01340308
• Record Type: Publication
• Report/Paper Numbers: 11-4115
• Files: TRIS, TRB
• Created Date: May 18 2011 11:43AM