Planning Tourists Evacuation Routes with Minimal Navigation Errors

Tourism is one of the largest growing industries worldwide, and so are the increased safety concerns. This is due to increasingly frequent and severe natural hazards as well as terrorism, where large crowds of tourists can be targeted. Furthermore, tourists are often less informed and are therefore more vulnerable to be trapped in chaotic situations. In such situations, normally we are interested in fast evacuation routes. However, tourists, especially during emergencies, are prone to orientation and navigation errors. Such errors can be avoided by providing electronic guidance at various intersections along the evacuation path (controlled intersections). This study formulates the above-mentioned situation as the shortest path problem with stochastic routing. The stochastic routing is the probabilistic selection of an outgoing arc at each node. As it is practically difficult to equip every intersection with guidance devices, a multi-objective model is developed. The model simultaneously minimizes the number of controlled intersections and minimizes the evacuation time gap between the proposed evacuation route and the optimal evacuation route. The problem is formulated as a stochastic multi-objective problem. A Pareto-front of solutions is obtained using a genetic algorithm and a simulation.