Research On Modeling And Optimization In Urban Area Traffic

With the rapid development of modern cities, residents have higher requirements to urban traffic. But the existence of urban traffic congestion is restricts the development of the city, which makes the citizen’s travelling inconvenient. Traffic signal control is a necessary traffic control measure to the bottleneck of urban road-the intersection, is also one of the effective ways to improve the efficiency of intersection traffic. In order to ensure the stabilization of the traffic network, it has important research significance to take reasonable measures to optimize the urban traffic signal timing.In this paper, urban traffic signal timing optimization which is based on improved the NSGA-II algorithm and enhancing the transmission efficiency by edge deletion were researched. The main research work is as follow:(1)The urban signal timing method and the characteristics of the macroscopic and microscopic traffic model are discussed. In order to more conform to the characteristics of urban traffic, the CTM model is improved. We conbine CTM model with traffic wave theory and vehicle following model, simulate a single intersection model, and verify the validity of this model. Finally, we build an urban regional traffic model.(2)The characteristics and steps of GA and NSGA-II are discussed. We improve the NSGA, use the arithmetic crossover operator, speed up the convergence of the algorithm. The improved NSGA-II algorithm is applied to the urban regional traffic model. As the maximum vehicle passing number and minimum average queue are the optimization target, we get the best scheme of the urban traffic signal timing. The timing scheme is simulate on CORSIM. The results show that the optimization method is effective and feasible.(3) Faced with the problem of urban traffic congestion, I introduce the edge deletion to urban traffic optimization. Then a certain strategy of enhancing the transmission efficiency by edge deletion which is based on betweenness is put forward. This method changes some of the vehicles’ driving path, so as to optimize the urban traffic condition. This strategy is applied in the traffic network model which has been established.The simulation results show that, in the optimization of urban traffic, enhancing the transmission efficiency by edge deletion is an effective and low cost strategy.