The Research Of Global Optimal Traffic Flow Guidance Algorithm Base On The Congestion Charge

In recent years, the amount of motor vehicles in China increases sharply. There have been35cities, which own over one million cars. Rapid growth in the number of cars to make traffic congestion has become a bottleneck restricting urban development. In this paper, we propose a kind of traffic congestion charge based on the real-time road condition, which as the weights of the road in the optimal route guidance algorithm of global traffic flow.The core idea of the algorithm is iteration. The realization process is as follow:First we calculate the value of the congestion charge and treat it as the weights of the road. Second we find several optimum paths based on the starts and the ends, and select recommended routes from these, not only the least value of the weights but each path has the opportunity to be selected. Then we update the road parameters, and count the total driving time taken by the vehicles. If the result is convergent, the recommended routes are the global optimal paths, if not, we need to recalculate the congestion charge based on the current road conditions and iterate continually.There are two innovations in the article. The first one is the road congestion charge determined by the real-time traffic, the road attributes and historical traffic volume. The real-time congestion charge can make part of the price-sensitive users shift from congested roads to the smooth ways, playing a role to distribute traffic flow reasonably. The other one is system equilibrium. Now many guidance algorithms are based on the criterion of user equilibrium, such as the least time, the shortest distance, which is easy to cause congestion when large number of drivers use and follow the ways of the induction. The ways generated by the global optimization criterion contain certain of randomness, and can be good to avoid this phenomenon.The main work of this paper contains:(1) study the road congestion charge model,(2) design the global optimal guidance algorithm based on the price,(3)simulate and test the performance of the algorithm in the simulation and the real road network existing several induction algorithms. From the results, the proposed algorithm can significantly improve the crowded road conditions.