Research On Urban Road Network Traffic Operating Efficiency Assessment

Beijing Declaration:China’s Urban Transportation Development Strategy "states that" the fundamental purpose of the urban transport is completing people’and things’ moving, rather than the transportation of individuals mobile. For the definition and classification of urban road traffic state are basically starting from the traffic congestion, that is, consider the feelings of the traffic participants and traffic mobility. Urban road traffic, however, as the transport activity of the carrier, its most fundamental goal is to be completed in under certain conditions a certain amount of transportation tasks. As a result, this paper introduces the concept of traffic efficiency, to assess the traffic running state of the urban road network.The traffic efficiency is an important parameter of the characterization of network operation quality, to evaluate the planning road network in the existing research, that is, static road network. If this indicator is into a dynamic road network status assessment, requires based on the actual situation to the new definition. This paper, from the fundamental significance of the traffic, take full account of the traffic flow characteristics, select the traffic flow (or od demand) and running speed as a parameter for calculating the efficiency indicators, define the transport efficiency being The actual completion of the traffic and the maximum traffic under certain traffic conditions. Its significance is that road traffic should also meet certain traffic demand at the same time ensure its smooth degree.Firstly, this paper deeply analyzes the assessment methods of the existing road network traffic. Evaluation of the traffic state of the roads and intersections is selected traffic parameters as the evaluation index; for the assessment of the state of network traffic, there is a comprehensive index evaluation method, reachability, connectivity analysis method, reliability analysis method, static efficiency analysis method, etc. Index evaluation method are mostly used in the evaluation of the midpoint of the road network (intersection), line (road), and such evaluation methods starting from the traffic flow, the comfort of the traffic participants point of view, while less consider the transport capacity of the road. F the state assessment method of the road network, Its starting point more to consider network analysis, usability, interoperability is not strongSecondly, based on the analysis of the dynamic efficiency of the Road Traffic, this paper gives the definition of the section and intersection traffic efficiency, and methods of computation; and detailed analyzes the application of transport efficiency indicators in the assessment of road traffic state. It proposes the efficiency-congestion match analysis method. This method comprehensively analyzes of road traffic state from the two key points of the transport capacity and speed of road traffic. The results can be better guidance on traffic control and management.Thirdly, the paper focuses on the efficiency of network traffic, and gives its computational model. The model is based on network OD demand, select the OD demand and the speed as the calculation parameters, search for the critical path between the OD pair while the road network is equilibrium, calculate the of the transport efficiency of critical path, extract the critical path consisting of the key road network to calculate the critical network traffic efficiency, and give improving analytical methods based on the calculation model.Finally, in this paper, Tianhe District, Guangzhou core regional road network as object of study, applies the proposed transportation efficiency assessment methods, analyzes the traffic efficiency of the road network, and give the recommendations for improvement to the way out network traffic. The calculated results show that the proposed method is reasonable, feasible, easy to operate, can be applied to the urban road network for state assessment and analysis, guide to make the measures of the traffic management control program.