Research On The Optimization Of Mountainous City Traffic Trip Distribution Model Under Constraint Of Critical Channel

Restricted by the terrain conditions,the network structure characteristics and traffic travel features of mountainous city has big different from plain city. Due to the natural separation of mountain, natural water bodies and the restriction of land conditions, narrow channel connecting the two areas of mountainous city often become the traffic bottlenecks in road network and restrict the inter-regional traffic travel,so it is the crucial channel linked inter-regional transport. The crucial channel constraints has a significant impact on the traffic travel distribution of mountainous city,but it is not fully reflected in existing traffic models, the traffic model is necessary to be improved. For this, this paper carries out related work on the optimization of traffic model under constraint of crucial channel.First,this paper analyzes the impact of crucial channel to the traffic of mountainous city,has a comparison of principles and methods of traffic travel distribution and deeply analysis the effect of the traffic travel spatial distribution and time distribution under constraint of crucial channel.Then,this paper points out the problems of existing traffic model and proposes the idea of model optimization.At last,this paper has a deeply study of peak hour traffic model constrained by crucial channel,set crucial channel road network peak-hour traffic volume as an boundary condition to determine the peak-hour factor of peak hour model,this method can make the peak-hour factor determined more optimized.Besides,this paper proposes sub-regional approach to optimize the peak hour trip distribution model.The main contents of the following areas:①Analyzes the impact of crucial channel to the traffic of mountainous city.First, summarily describes the concepts mountain city.Then, detailed analysis mountainous city’s traffic and road network sructural characteristics. On this basis, analyzes the impact of the traffic characteristics under constraints of crucial channel.②Detailed analysis traffic trip distribution model. Based on the elaborating of the traffic model and four-stage method,comparative analysis the basic principles, the advantages and disadvantages and the applicability of traditional transport travel distribution model.Detailed analysis the characteristic of the traffic travel distribution from time distribution and spatial distribution.③Focus on the impact of constraints on the critical path mountainous city traffic travel distribution model and the optimization of model. First elaborated the characteristics of traffic demand, detailed analysis the impact of critical channel constraints to the traffic travel spatial distribution and temporal distribution,then separately pointed out the problems of prior model and provides a guideline of the model optimization. On the basis of in-depth analysis the problem of existing peak hour the model, deeply studies the impact of critical channel constraints to peak hour trip distribution, offeres crucial channel road network peak-hour traffic volume as peak-hour factor determined boundary condition and optimizes the peak-hour factor determining. Using sub-regional peak-hour factor to optimize the peak hour trip distribution model.④Finally, the main city of Chongqing as an example to carry out case studies. Combined of the geographical features and current traffic model,demonstrates the critical channel constraints has significant affectes on the traffic channel spatial distribution and temporal distribution. Verifies that the optimization of the peak hour trip distribution model is scientific and practical.