Research On Methods Of Traffic State Identification Based On Fixed Detector

In recent years, with the rapid development of our social and economic, urban transport structure and traffic conditions also changed dramatically:On the one hand, the rapid advance of urbanization promoted the growth of road mileage and the improvement of road network structure; On the other hand, the rapid growth of cars, causing traffic demand growing much faster than the traffic supply capacity. Which led the traffic congestion more badly, the mileage of congested road was increasing, the congestion periods also increased significantly.According to statistics, two-thirds of our cities had traffic congestion problem in "peak" periods. Traffic congestion not only led to frequent traffic accidents, increased vehicle delay and vehicle emissions, but also had a serious impact on social and economic sustainable development; people's daily lives and work were disturbed. Thus, taking the necessary measures for traffic management and traffic control, easing urban traffic congestion which caused social and economic pressure, become a problem to be solved. The regional traffic status discrimination is the prerequisites for traffic management and traffic control. Therefore, the research of regional traffic state identification was focused on by domestic and international transportation experts. This paper analyzes the state distinguishing aspects of regional transport research status at home and abroad, quantifies the imbalance of the road network and the traffic flow based on the unbalanced characteristics of the traffic states. Analysis the regional traffic states from point to surface, finally, the state of the entire regional transportation were analyzed and discriminated.The first part introduces the research background, purpose and significance of this research. Meanwhile, this part establishes frame structure of the paper based on the review and summary of research results both at home and abroad, thus lays a foundation for subsequent research work.The second part analyzes the imbalance of road network, the respective characteristics of road sections and intersections were analyzed, and the topology of the road network is analyzed and expression using graph theory. Finally, on the basis of the selection of traffic flow parameters and the layout optimization of the detector, determine the traffic flow parameters which can expression the traffic state of the network element and the layout of the detector.The third part selected the traffic flow parameters which can express the traffic state of the road sections and intersections and establish the state identification model of road sections and intersection based on the analysis of the traffic operation characteristics of the road sections and intersections; In order to quantify the imbalance of the road sections and intersections, the weight models were established; the regional traffic state model was established based on the comprehensive analysis of the affect of network element state, and the index of regional traffic state was confirmed.The forth part analyzes the manifestation of the overall state of the road network, and study the intuitionist and validity of the macro-traffic state parameters which express the regional traffic state. The methods for determine the state level was confirmed based on the analysis of the relationship between the state index and the macro-parameters, and determine the congestion level.The fifth part validate the state identification method using micro-simulation software. Firstly, create the appropriate network and the simulation environment in VISSIM; then, design the simulation program and select the evaluation index; finally, analysis the simulation results based on the simulation data, and discriminate the effect of the methods for regional state identification.The last part of the paper gives a summary of the full text, and reviews the research contents and progress of this paper, finally, puts forward the issue to be further explored.