Evacuation Assisting Strategies in Vehicular Ad Hoc Networks

Recent natural and man-made disasters such as Sandy (2012) and Fukushima nuclear power plant (2011) make efficient evacuation route planning and routing more important than ever. Conventional sign-based evacuation route and its information are limited to use in a life-threatening environment. In this paper, we first investigate a least travel time based shortest path approach to minimize the evacuation time in a Vehicular Ad hoc Network (VANET). Since the travel time changes in the presence of time-varying traffic congestion, frequent and timely updates of the shortest path during the evacuation period are essential. Thus, we also investigate an evacuation assistant VANET to efficiently update the shortest path on wheel by using Vehicle-to-Infrastructure (V2I) and Vehicle-to-Vehicle (V2V) communications. Then we propose evacuation assisting schemes, V2RSU and V2RSU+V2V. We also implement the shortest path based schemes to work in VANETs, Lowerbound and W/O_Update. We compare the performance of four schemes as a function of the number of congestions, sources, destinations, and vehicles and different network sizes. The simulation results indicate that the proposed schemes integrated with a VANET can reduce the evacuation time significantly.

I. Introduction

With increasing risks from natural and man-made disasters, efficient evacuation plans play a critical role for lifesaving in disaster and emergency preparedness. For example, a tsunami caused by a 9.0 earthquake damaged three nuclear reactors at the Fukushima Daiichi nuclear power plant in 2011. Over 170,000 people were evacuated and dispersed from the surrounding areas [1]. Global warming impacts the creation of super storms like Hurricane Katrina (2005), Rita (2005), and Sandy (2012). Recent Hurricane Sandy affected East Coast and 24 U.S. states, particularly damaged New York City, which is the largest city in U.S., and called mandatory evacuations for over 375,000 people residing in seashore and low-lying areas [2]. Although several U.S. states (i.e., Louisiana, Mississippi, Florida, Texas, etc.) primarily use a signed evacuation route, which simply shows a direction and radio channels for information, its effectiveness is very limited in a life-threatening environment.