An offline mobile application for automatic evacuation guiding in outdoor environments

When a large-scale disaster occurs, evacuees have to move to safe places speedily, under highly stressful situations. For this purpose, an automatic evacuation guiding scheme based on unconscious cooperation between evacuees and their mobile nodes has been proposed and its performance, e.g., average/maximum evacuation times, has been well studied through simulation experiments. In this paper, we focus on the mobile application, which plays the key role of the automatic evacuation guiding scheme. The mobile application should be designed to operate even under offline environments because it may be disconnected from the network due to highly damaged communication infrastructures. We first design such an offline mobile application with required functions, i.e., positioning, estimation of evacuees’ situations, process of road network data, and presentation of useful information. Since positioning data obtained by Global Positioning System (GPS) may include errors, we also propose a scheme to estimate the evacuees’ situations, e.g., current position on road network and encounter with blocked road segments, by applying map matching algorithms, which try to identify a correct position and a road segment of an evacuee from erroneous positioning data. We further implement the offline application on an actual mobile phone. Through experiments, we evaluate the fundamental characteristics of the application, i.e., GPS positioning accuracy, processing time, and continuous operating time. Furthermore, we show the effectiveness of the proposed scheme in terms of estimation accuracy of an actual evacuation route, and that of blocked road segments.