Optimization Study On Road Emergency Evacuation Routes Base On Improved Ant Colony Algorithm Ang GIS

In recent years,along with the rapid formation of the trunk road network,the traffic demand develops rapidly and road traffic incidents also occurred frequently.Once the traffic incident occurs,it will affect the health of the road,result in varying degrees of traffic congestion and lead to environmental pollution and waste of energy and other issues.How to evacuate the traffic object that within the scope of the event to safe and unblocked region to reduce the impact of traffic event attracts more and more attention.Therefore,the regional road network traffic emergency evacuation when the traffic incident occurs is studied in this paper.First of all,this paper analyzes the optimal path algorithm,and finds that the randomness and parallelism of the ants in the ant colony algorithm,which has great similarities with the users’ the dependence of their known information and historical experiences while traveling through in-depth analysis and study of a variety of intelligent optimization algorithm,for this reason,this paper applies the ant colony algorithm for the path search.Besides,this paper introduces link capacity function into the transfer rules,and the heuristic function uses impedance function as equivalent length instead of road geometry length,in order to ensure that the algorithms is more inclined to short transit time and large capacity sections in path search,Therefore,this paper proposes the improved ant colony algorithm that is suitable for the evacuation path.Secondly,this paper analyzes the traffic distribution model.Through the comprehensive analysis of the characteristics of different models,use conditions,the results precision of the models and the characteristics of the emergency evacuation,this paper applies the capacity limit model for traffic distribution,and uses the BPR function as the road impedance function.Then,this paper describes the road emergency evacuation and establishes a road network emergency evacuation model aiming at minimum evacuation time of road network with a comprehensive consideration of background traffic and traffic evacuation,and this paper proposes a double iteration mechanism to solve the model.Inner iteration applies this improved ant colony algorithm to find the origin-destination shortest path for the traffic flow load,and outer iteration applies capacity limit distribution method to update road impedance.Through the experimental analysis of ant colony algorithm parameters on the computational results and the impacts of the convergence rate,the optimal parameter combination is concluded,which is subsequently applied to the improved ant colony algorithm,then a reasonable and feasible road network emergency evacuation solution is obtained.Finally,this paper uses C # programming language in the development environment of VS2010 to design highway emergency evacuation path research systems based on ArcGIS Engine platform,and designs emergency evacuation paths,and also visualizes path information by using intranet highway network and thematic maps in GIS.This study aims at dealing with unexpected traffic eventspromptly and effectively,for the realization of rapid evacuation and emergency relief,in order to reduce casualties and economic losses.