Base On Spatial Direction Relations Of City Road Shortest Path Algorithm

With China’s urbanization must fast-paced, our country city continues to expand thescale of urban traffic flow increase, and turban traffic with great pressure。At present ourcountry all the big cities, were faced with traffic problems, among them with the trafficsafety problems especially serious. So, which requires us to social functions in there is atraffic accident to make a rapid response, to the scene of the accident involved,in time, tominimize the losses of lives and property, then relief vehicles travel the shortest path in therelief work plays a very key role. With the popularity of computer and geographicinformation science development, GIS for its strong function get wide and deep application.Network analysis, as one of the primary function of GIS, in electronic navigation, traffictourism, city planning and electric power, communications, and other various network,pipeline layout design plays important role in, the general network analysis functionincluding path analysis, resource allocation, connected analysis, function including pathanalysis, resource allocation, connected analysis, flow analysis, etc. Network analysis ofthe basic problem is the shortest path problem, in the traffic network analysis system playsan important role.This article through to the existing shortest path algorithm, such as the classic Dijkstraalgorithm, A*algorithm, genetic algorithm, the classical algorithm used is introduced, andtheir features are analyzed, the shortest path algorithm in storage space and efficiency alsothere are some problems, Dijkstra algorithm for network topology characteristics of onlyconsider or stage characteristic, ignoring the space distribution features of network, tomake the search process lack of direction. According to the characteristics of therelationship between space direction and in the function of GIS inquires, this paper basedon this, advances the direction of relationship based on space shortest path algorithm, itthrough the space in the space analysis of relationship between direction can be used as aconstraint, to improve the efficiency of the algorithm.