traffic signal timing for urban evacuation

Abstract

Significant effort has been expended to reduce the evacuation time in a geographic evacuation. The majority of these efforts have focused on freeways and it appears that there has been no systematic consideration of signal timing in evacuation planning for urban areas. However, signal control can greatly impact traffic flow in an evacuation. This thesis studies approaches for signal timing to facilitate evacuation and response in the event of a no-notice urban evacuation. A simulation model was constructed with data from Washington, D.C. Experimental results indicate that significant trade-offs exist in setting timing plans as long cycle lengths can lead to reduced evacuation times, but at the expense of delay on minor roadways. Best compromise plans employ cycle lengths greater in length than used in ordinary peak hour plans, giving significantly more green time to the main evacuation routes than to minor roadways as used in peak hour plans.