DisastersPlanning traffic routing in no-notice disasters

Published 21 May 2012

Spontaneous evacuations of New York City and Washington, D.C. following the 9/11 terrorist attacks demonstrated that U.S. cities are not prepared to manage the sudden influx of traffic into roads and highways following a no-notice disaster

The Mineta Transportation Institute has released its newest peer-reviewed research report, A Framework for Developing and Integrating Effective Routing Strategies within the Emergency Management Decision-Support System. It describes the modeling, calibration, and validation of a multi-modal traffic-flow simulation of the San Jose, California downtown network. It also examines various evacuation scenarios and first-responder routings to assess strategies that would be effective during a no-notice disaster. Other cities can use the models to plan their own emergency traffic routings.

Spontaneous evacuations of New York City and Washington, D.C. following the 9/11 terrorist attacks demonstrated that U.S. cities are not prepared to manage the sudden influx of traffic into roads and highways following a no-notice disaster,” said Dr. Anurag Pande, one of the study’s authors. “For many years, anticipated events such as hurricanes have been the basis for evacuation planning. Now we see increasing interest in evacuation planning based on hypothetical no-notice events.”

Pande noted that advances in computing technologies have made it possible to simulate urban transportation networks in great detail with programs such as VISSIM, which was used in this study.

These traffic simulation models can be used to devise strategies for evacuation and emergency response in the event of a disaster.

The modeled network required a large amount of data on network geometry, signal timings, signal coordination schemes, and turning-movement volumes. Turning-movement counts at intersections were used to validate the network with the empirical formula-based measure known as the GEH statistic. This measure is used in traffic engineering and traffic modeling to compare two sets of traffic volumes.

Once the base network was tested and validated, various scenarios were modeled to estimate evacuation and emergency vehicle arrival times. Based on these scenarios, a variety of emergency plans for San Jose’s downtown traffic circulation were tested and validated.

The study’s authors say that by entering their local data, other communities can leverage this framework to evaluate their own emergency scenarios. The models also can be used to help train emergency responders, who can see the immediate results of specific decisions. They can also help communities plan traffic flow for road closures, construction, major events, and other situations that affect mobility.

The complete report includes thirty-seven figures and fifteen tables for illustration. Chapters include Traffic Simulation: Discussion and Literature Review; Network Modeling; Alternative Disaster Scenarios; and Conclusions, Emergency Management Applications, and Future Scope.

Free copies can be downloaded from the Institute’s Web site.

— Read more in A Framework for Developing and Integrating Effective Routing Strategies Within the Emergency Management Decision-Support System