Research On The Evaluation Methods Of Traffic Flow Organization Of Urban Traffic Network

One-way street, convertible lane, left-turn prohibiting are three kinds of common forms of traffic flow organization(TFO), which can realize the reasonable use of existing road resource by eliminating the opposite vehicle effect, adapting the changing traffic conditions, alleviating conflict at intersection. With ever-growing traffic demand, it is believed that TFO is one of important means to improve efficiency and handle congestion. Meanwhile, there are both advantages and disadvantages for the intensive influence of TFO. Hence, the key problem of TFO research is evaluation method of organization plan.TFO is a kind of traditional traffic management technology. However, its extensive use begins in 1990's in China. Nowadays, efficiency one-way street networks have been established in Qingdao, Dalian and other place. Convertible lanes are put in use in Beijing, Shanghai and other place. Left-turn prohibiting is a common form in artery management. Although TFO received expected effect in someplace, it should be noted that TFO plan resulted in failure and fluctuation in some city, which not only cause the huge waste but also restrict the develop of TFO. In fact, theoretical guidance is relative scarce in TFO practice. In recent years, a great deal of research about TFO has been done by traffic managers and scholars. However, the research about influence analysis, enforcement condition ,evaluation method of TFO need to be strengthen. Moreover, some one-way streets are converted back to two way in some north America city. Generally speaking, it is a urgent need to develop enforcement condition and evaluation method based on China'traffic feature ever-growing traffic demand. According to this, this doctor dissertation focuses on TFO, which was supported by National Natural Sciences Foundation of China through the key project(Grant No. 50338030) and National Basic Research Program of China(Grant No. 2006CB705500). More practical conditions and travel cost evaluation method are developed in the dissertation based on the thorough analysis of influence. This dissertation is consisted of the following chapters interrelated to each other.(1) The first chapter is introduction. Firstly, the research scope of TFO is restricted. Secondly, the importance and feasibility of comprehensive research is given. For the obvious discrepancy existing in domestic and international TFO research, contrast summary of TFO implement and research is provided. The last part of this chapter is a brief introduce of research content.(2) Analysis of TFO influence and count measure. The research goal is divided into users and system. The first level is user. For traffic users, they are consisted of pedestrian, cyclist and driver. Influence and count measure of each user are researched. The importance of evaluation for social vehicle efficiency is pointed out. For non-traffic users, the complexity and substance of influence is deduced. The inquiry method is introduced. The present count measure is given. The second level is system. The changing after TFO enforcement occur in network structure, capacity of road segment, v/c, and capacity of road network. All this changes result in vehicle efficiency change.(3) Enforcement conditions of TFO. For one-way street, the shortcomings and reason of present research are pointed out. The key advantages and disadvantages of one-way street are analysed. The judgment methods and flow charts of one-way street are given. The calculation methods of traffic load and lout-of-direction travel distance are developed. For convertible lane, the basic conditions suitable to present character is provided based on the famous design manual. For left-turn prohibiting at signalized intersection, calculation methods of out-of-direction travel distance of left-turn vehicle are developed according to OD distribution. For left-turn prohibiting at unsignalized intersection, the change of travel route and running state is comprised(4) Evaluation methods of TFO based on the travel cost. A brief introduction of present evaluation is given. The methods include comprehensive evaluation, simulated appraisement, and network optimization. Based on the conclusion of TFO influence analysis, the importance of travel efficiency is clarified. Hence, evaluation goal in this dissertation is vehicle running efficiency. Based on user route choosing behavior, the importance of travel distance evaluation is verified. Based on the travel cost theory, the travel cost evaluation method and flow chart are developed combined with calculation and comparison method of travel time cost and travel distance.(5) Enforcement methods of TFO evaluation. According to the traffic assignment theory, the enforcement methods are developed. The differences in TFO evaluation comprised with traffic planning include evaluation scope, OD inquiry, travel cost model, and traffic assignment algorithm. Because of the complexity of forecasting model about travel time, the speed-flow characteristics and influence of transit vehicle are the main research content. Based on the field work of traffic flow in Changchun city, scatter charts of speed-flow data are plotted to elucidate linear regression equations of scatter plots and their boundary. The delay model is established based on the queuing theory and gap acceptance theory for light and heavy flow condition.In the end, the dissertation summarizes the findings and achievements and brings forward the issues for further research.