The Model Of Traffic Status Distinguish For Urban Road Network Based On Analysis Of Node Accessibility

With the city's economic development, regional road networks have been expanding and improving. However, the continuous development of network capacity has not improved the growing traffic congestion problem, the contradiction expose problems in the urban traffic management, that is expanding the road network is only temporarily alleviate the current capacity of the transport supply and demand, and effective solution is to rely on advanced management tools and methods, real-time informed of the micro-node and macro-sections of the traffic network state information, and timely release to travel by road traffic in order to avoid the congested areas to improve network utilization Purposes. Therefore, to achieve the state of urban road network traffic in real time and accurate identification has become a priority.Research about section traffic status distinguish on the network level at home and abroad is few, and most of the research is the unexpected traffic incident identification technology aimed at a section. The biggest problem is that technology can not meet the traffic control department of the state judge to run real-time requirements. Because traveler more concerns the current all the traffic condition of intersections and sections of network, in order to make their own decisions on travel routing choice For The city roads are complex topology, travelers are faced with numerous access roads to choose the best combination, therefore, the identification of urban road traffic state in real time needs to start from the entire road network. Real-time quality of service and traffic state of each intersection and sections need to feedback to management fully and timely so that they can publish real-time traffic status information. In addition, with the increasing demand for road traffic, traffic jams often evoked more and more common which is unrelated to traffic accidents, and the identification of such traffic state is becoming an important part of management attention.In this paper, taking full account of road traffic participants and managers real-time traffic status information requirement, based on the network microscopic traffic flow characteristics and the complexity of the road network, I deeply analyze the impact on the micro flow on the sections about network characteristics of traffic such as layout structure of urban road network and topology. Based on the comparative analysis on traffic status parameters, with the connotation of urban traffic state identification, an evaluation indicator of discriminant model was proposed. Finally, according to international standards to quantify the traffic status, a traffic model was established, and the node reachability analysis method introduced, the road network congestion state of the adjacency matrix and the intersection of up to matrix were structured, and the example show that the method was real time and high accuracy.This paper has certain characteristics as follow:(1)With the analysis of network complexity, defined impact of the macro-network structure on the traffic status on the micro-traffic. Analyzing of the common traffic parameters, with the connotation of urban traffic state identification, based on saturation and dimensionless speed of the traffic state identification indicator was proposed for this article;(2) Analyzing the performance of traffic state of classical discriminant model, combined with the performance of the model of urban road user needs, with the introduction of node reachability analysis, building roads congestion status of the adjacency matrix and intersection of up to matrix, the road network identification model was build based on reachability of node;(3) Clearly identified the discriminant cycle of the model and the model status change threshold values.