Automatic evacuation guiding scheme based on implicit interactions between evacuees and their mobile nodes

Abstract

When large-scale disasters occur, evacuees have to evacuate to safe places quickly. They, however, may not be able to afford to obtain sufficient information for their evacuations under such emergent situations. In this paper, we propose an automatic evacuation guiding scheme using evacuees' mobile nodes, e.g., smart phones. The key idea to achieve automatic evacuation guiding is implicit interactions between evacuees and their mobile nodes. Each mobile node tries to navigate its evacuee by presenting an evacuation route. At the same time, it can also trace the actual evacuation route of the evacuee as the trajectory by measuring his/her positions periodically. The proposed scheme automatically estimates blocked road segments from the difference between the presented evacuation route and the actual evacuation route, and then recalculates the alternative evacuation route. In addition, evacuees also share such information among them through direct wireless communication with other mobile nodes and that with a server via remaining communication infrastructures. Through simulation experiments, we show that 1) the proposed scheme works well when the degree of damage is high and/or road segments are continuously blocked, 2) the average evacuation time can be improved even in small penetration ratio of the proposed system, and 3) the direct wireless communication can support many evacuations at almost the same level as the communication infrastructure when the number of evacuees becomes large.

Congestion-aware route selection in automatic evacuation guiding based on cooperation between evacuees and their mobile nodes

“…Various studies have been done for evacuation support in large-scale disasters and some of them focus on traffic congestion caused by evacuation behavior [2,3,[5][6][7][8][9]. These are mainly divided into two types: analysis of evacuation behavior based on disaster simulations and field survey [3,5], and evacuation guiding using information and communication technology [2,[6][7][8][9].…”

“…These are mainly divided into two types: analysis of evacuation behavior based on disaster simulations and field survey [3,5], and evacuation guiding using information and communication technology [2,[6][7][8][9].…”

“…The shared information will improve the evacuation movement of evacuees. Since it may be difficult for evacuees to register the information to their mobile nodes in emergent situations, Komatsu et al propose an automatic evacuation guiding based on implicit cooperation between evacuees and their mobile nodes [2]. Komatsu et al also propose an information sharing scheme called On-Demand Direct Delivery for the automatic evacuation guiding, which can reduce the network load compared to the existing DTN routing [11].…”

“…There are some studies that assume local information sharing can be achieved by ad hoc networks [6,12] and DTNs [2,7]. Since the proposed congestion-aware route selection is conducted over the automatic evacuation guiding [2], we apply the DTN-based information sharing.…”

“…In [2], the performance of the automatic evacuation guiding scheme is evaluated from the viewpoint of average/maximum evacuation time among evacuees, under the situations where the recommended route is given as a shortest path and traffic congestion does not occur. In actual situations, traffic congestion may be caused by evacuation behavior.…”