A Study Of Traffic Bottleneck Based On Simulation Technology

Traffic bottleneck is the key point of traffic system. Enhancement of the capacity in bottleneck area will improve the integrate operation performance of traffic network effectively. Based on traffic simulation technology, this thesis carried out a series of studies on bottleneck. Mainly three parts are included in the paper, which are locating and ranking of bottleneck in road network, analyzing of bottleneck and improving of bottleneck respectively.Locating the bottlenecks and ranking them according to their impact degree are a prerequisite to figuring out improving measures. First, a locating and ranking algorithm, based on Theory of Constraints (TOC), is put forward. Then,other methods aimed at different traffic measures of effectiveness are respectively advanced, which are the capacity method, delay method, speed method, investigation vehicle method, queue length method and density method respectively. Following that, the Unified Level of Service Analysis Method (ULOSAM) is put forward,in which uniform measures and procedure are adopted in the evaluation of level of service (LOS) of network. Based on Fuzzy Synthetic Evluation (FSE),a network LOS evaluation method is advanced and an illustration example is given.In order to analyze the bottleneck in detail, Cumulative Curves of Vehicle Count (CCVC) and Traffic Wave Theory (TWT) are summarized, with the character and application scope analyzed. On the basis of these, traffic simulation method is presented, which overcomes the defects of both methods mentioned above and is therefore useful.The formation of bottleneck is caused by a variety of factors, and it is a system project to analyze the reasons and to put forward improving measures. Taking this into account, this dissertation studies specific problems in the form of application example by means of TSIS. The first example focuses on the importance of intersection enhancement. A comparative study is carried out between the effects of intersection enhancement and arterial widening on a given road network. The second example is mainly about signal controlled intersection, which finds out that the sigal machine shall be turned off when traffic volume is small in order to save travel time. When bottleneck causes serious traffic problems, traffic diversion shall be considered. The third example inquires into this matter with traffic simulation as a tool.