Study On The Key Problems Of Node Traffic Connection Of Urban Expressway

The effect of urban expressway is very important, because it can ensure urban smooth traffic, reduce the growing pressure on urban traffic, keep an effective separation between the long-distance traffic and the short-distance traffic, convergent and transit urban internal roads and external roads reasonably. To ensure the effectiveness of urban expressway system, reduce the traffic pressure of expressway and achieve orderly operation of nodes'traffic, it is necessary to do scientific and rational research on the traffic convergence of expressway nodes and related urban roads, achieve an organic integration of urban expressway and overall urban roads network, and accelerate the order development of the urban road traffic.Based on the functional characteristics of expressway, this thesis will research three key issues about urban expressway nodes from the view of planning: traffic macor-convergence ,traffic micro-plannng and evaluation of traffic convergence.As to macor-covergence,focused on the convergence of both line level and network level, the thesis studies the expressway nodes and urban roads network's structural covergence,then presents the traffic distribution model for expressway and related roads based travel choice;about nodes trffic micor- plannng, in light of the actual, it analyses the functional characteristics and setup conditions of the common expressway interchange; researches the minimum distance of expressway's entrance and exit; puts forward the calculation for the length of the main interwined roads;in regard of traffic convergance evaluation expressway nodes,according to influencing factors about expressway nodes'efficiency, the thesis puts forward the convergance evaluation index system, and applies fuzzy synthetic evaluation method to assess the reasonable degree of convergance. Combining with traffic analysis of the southeast of the second loop-line of Changsha, the thesis advances the traffic rebuilding programs,which is the good application of this reseach.In the current research, there is still room for promotion in the theoretical research on urban expressway nodes connection. This thesis presents improved solution to the key issues in the expressway traffic through the effective integration and process on the given theory and methodology ,and provides a scientific reference for urban expressways'planning, construction and reform.