Effects of shadow evacuation on megaregion evacuations. (June 2020)

• Record Type: Journal Article
• Authors: Zhang, Zhao; Herrera, Nelida; Tuncer, Efe; Parr, Scott; Shapouri, Mohammad; Wolshon, Brian
• Is Part Of: Transportation research. Volume 83(2020)
• Publication Date: 2020-06
• Subjects: Megaregions -- Shadow evacuation -- Simulation -- TRANSIMS -- Emergency; Transportation -- Research -- Periodicals; Transportation -- Environmental aspects -- Periodicals; 354.76
• DOI: 10.1016/j.trd.2020.102295
• Languages: English
• ISSNs: 1361-9209

Abstract

Highlights: An agent-based simulation model for shadow evacuation analysis. Effects of unnecessary shadow evacuation on the whole traffic in megaregions. Shadow evacuation rate did not significantly impact evacuation clearance time. Shadow evacuation choke location will cause significant congestion. Abstract: Transportation systems serve important roles during emergencies, in particular for evacuations. However, efficient travel during these life-and-death scenarios can be adversely impacted by external conditions, such as unnecessary and unneeded travel. This research sought to enhance the understanding of the effects of these conditions by analyzing shadow evacuations, and their impact on regional traffic operations in megaregions, more broadly. The research was based on simulations of a range of hurricane evacuation threat scenarios in the Gulf of Mexico building upon prior study using TRANSIMS . These assessments are also targeted at what many assume could be worst case evacuation conditions and pushing the limits of current simulation modeling capability. Among the broader findings of this work was that shadow evacuation participation rates did not significantly impact the evacuation clearance times within mandatory evacuation areas of the megaregion as long as demand could be temporarily spread out. This finding does not, however, suggest that the shadow evacuations have no impact on evacuation processes. High rates of shadow evacuees can cause significant congestion if they are not able to exit critical routes before mandatory evacuees reach areas further away from the coast.