The Optimal Routing Of Fire Engines Considering UncertainFactors

It is important tiiat fire forces can arrive the location in time to rescue when facing an outbreak of fire. As a component of the traffic flow,fire engine is influenced by real-time traffic conditions and unexpected traffic accidents. Because of all these factors,travel time from the fire center to the fire location is uncertain. Besides, optimization routing problem of fire engines is different from routing problem of public vehicles. Firstly, fire engines require hi函 level of reliability,which need to be guaranteed during routing. Secondly, time is the most important goal while other factors such as costare not so important, thus the criterial of routing policy is to save time. Last,fire engines do not need to follow traffic rules such as traffic signals, one-way road. Thereforewe need to take the reverse road into consideration when planning routes.According to the attributes we mentioned above,in this article the road network is assume to be stochastic and travel time is assumed to be random variables, stochastic network and time independent network is taken in to consideration as the foundation of the network after the analysis of the criteria used in stochastic network, and according to the assess principle used by fires department, we adopts cx-reliable and average travel time as our biobjective of the routing problem. The label correcting algorithms is improved by the extension of Bellman optimality principle, different algorithms is given is this paper to solve the problem. Then, the adaptive-routing policy is adopted to determine the routing policy when navigation. And we present an algorithms to solve it. At last,the center area of Dalian is selected to assess the speed of the algorithms.The result shows that,the biobjective can perfectly reflect the decision process of fire engines. And it is possible for the algorithms to handle the scale of urban network.