Research On Traffic Congestion Degree Determination Method Based On VHT For Road Networks

Under the situation of increasingly rapid urban development in our country, theroad network scale is also expanding, traffic congestion has become a worldwideserious problem, especially in cities with large scale network. The complexity ofnetwork and large traffic demand more intensifies the traffic problem. To develop areasonable delay blocking measures and traffic development policies, it is ofparticularly important to evaluate the road network traffic congestion degree.Therefore, the dissertation puts forward the traffic congestion degree evaluationmethod from the macro level to micro level for commonly traffic jam phenomenonbased on the traffic evaluation indicators and evaluation methods both at home andabroad on the basis of different indicators to judge. It evaluates the single road, thesame grade road and the overall road network respectively.First of all, the dissertation analyses the influence of continuous flow facilitiesand cutoff facilities to the traffic flow respectively based on the analysis of large-scalenetwork traffic congestion characteristics, all levels of road traffic flowcharacteristics and road network structure. It puts forward two aspects from the microand macro level together to build urban traffic congestion degree judgment indexsystem. Secondly, it refers the classification principle of traffic congestion degree ofservice level at home and abroad, determines the basic sections, diverging andmerging area of expressway, basic section of zero flow facilities and intersectioncongestion degree judgment index. It builds the sections-road-road network ishierarchical traffic congestion degree evaluation index system. Finally, the fuzzycomprehensive evaluation based on analytic hierarchy process (AHP) is used formicro section traffic congestion degree evaluated. Then it takes vehicle travel time(VHT) as an index of the traffic demand and put forward a traffic congestion degreeevaluation model based on traffic demand. With Xi’an big goose pagoda area trafficsituation, it has carried on the microscopic model validation.