Robustness of Transportation Networks under Megaregion Evacuations

Mass evacuations are a protective action to move large populations from hazardous areas to safety. However, even the best-planned evacuations can be slowed by unexpected disruptions, such as traffic incidents. Even minor disruptions can significantly slow evacuations, so it is critical to understand which links are most vital to the operation of the system. This paper describes a study to address that need by developing a method to evaluate large networks more efficiently to identify links that disproportionately increase network delay when affected by disruptive incidents. The study is unique because it examined the impact of individual link disruptions over a megaregional network covering thousands of square miles while drastically reducing the computation time necessary for a traditional full-scan analysis. In the research, link criticality was quantified by an index using factors such as alternative path availability, global maximum flow properties, modified betweenness centrality, and hazard exposure. Links with high indices established an initial “most-critical” list, then agent-based simulation was used to quantify the network-wide effects of disrupting these most-critical links. Results showed that links with the highest indices often had the fewest alternative paths to avoid them. Thus, while incident effects tended to be localized, findings suggest that networks with more path alternatives tend to have higher overall resilience to disruptions. By giving the ability to reduce computational efforts to evaluate large-scale networks, this methodology can be used in emergency planning to focus monitoring on the most important areas and allow them to be monitored for disruptions to maintain network efficiency.

• Record URL:
  • https://sites.utexas.edu/cm2/files/2024/12/No.46_Year3_Wolshon_Robustness-of-Transportation-Networks-under-Megaregion-Evacuations.pdf
• Supplemental Notes:
  • This document was sponsored by the U.S. Department of Transportation, University Transportation Centers Program.
• Corporate Authors:

  University of Texas, Austin

  School of Architecture
  Austin, TX  United States  78712-1075

  Louisiana State University, Baton Rouge

  Department of Civil and Environmental Engineering
  Baton Rouge, LA  United States  70803

  Cooperative Mobility for Competitive Megaregions (CM2)

  University of Texas at Austin
  Austin, TX  United States  78712

  Office of the Assistant Secretary for Research and Technology

  University Transportation Centers Program
  Department of Transportation
  Washington, DC  United States  20590
• Authors:
  • Wolshon, Brian
  • 0000-0002-1703-2995
• Publication Date: 2023-4

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Maps; Tables;
• Pagination: 18p

Subject/Index Terms

• TRT Terms: Disaster preparedness; Evacuation; Metropolitan areas; Network analysis; Network links; Traffic delays; Traffic incidents
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; Security and Emergencies;

Filing Info

• Accession Number: 01941918
• Record Type: Publication
• Report/Paper Numbers: CM2-46
• Contract Numbers: 69A3551747135
• Files: UTC, TRIS, USDOT
• Created Date: Jan 8 2025 9:40AM