Research Of Dynamic Optimal Traffic Route Algorithm Under The Environment Of GIS

Road traffic is closely linked with people's life and production activities, while with the development of the society and economy and the living standard of people, the pressures traffic transportation is facing are greater and greater. The problems such as traffic jam and traffic accidents and environmental pollution caused by traffic become seriously day by day, in order to solve these problems, Intelligent Transportation System (ITS) emerge as the times require, and Geographic Information System as a base platform of Traffic Geographic Information System (GIS-T) has obtained extensive attention. The problem of dynamic optimal traffic route under the environment of GIS studied in this paper is one of the most important subjects in ITS researches. The research in this paper can help drivers to save travel times and expenditure on fuel, can increase the utilizing efficiency of current traffic facilities, can reduce the automobiles' emission of greenhouse gas and protect the environment, and so on, has certain theoretical significance and practical value.The thesis studies the related technologies of dynamic optimal traffic rout algorithm under the environment of GIS, the main contents involve: Use ArcGIS software family as the application platform and building the network dataset of traffic network under the environment of ArcInfo 9.2; Study and analyze the foundation of the traffic network dynamic weight model, build a dynamic weight modal for roads based on k-nearest neighbor nonparametric regression method. The experiments verified that the model can use the historical dates and actually measured dates properly to predict the state of the traffic network accurately; Use the Ant Colony Algorithm (ACA) to implement the solving of dynamic traffic optimal route under the environment of GIS. The paper introduces the basic ACA model and analysis the searching characteristics of ACA. For overcome the deficiencies such as local optimal solution and long time researching which appeared when ACA is used in large-scale traffic network optimal route problems, the basic ACA is improved in some aspects such as the direction guide and pheromone update, and these improvements make the ACA become more suitable for the optimal traffic route searching. The selections of ACA's parameters are based on the experiment research, and a relatively good combination of parameters is obtained, and the experiment is also verified that the improved ACA performs better than the basic ACA; Realize the dynamic traffic optimal route algorithm based on ArcGIS platform in Visual Studio. NET 2005 programming environment, the development language is C#.The algorithm which studied in this thesis can more accurately find the best way between the two points in the traffic roads net .What's more, it can adjust the search rout according the road's traffic state and turn restriction and provide the rational road plan.