Infrastructure Study On The New Expressway Entrances Of Chongqing Inner-ring Roads

Urban expressway is the artery of any urban network system. It is one of theimportant measures to alleviate urban traffic congestion. An Urban expressway canmitigate heavy traffic flow and travel long distances at high efficiency in cities. Urbanexpressways play an important role in the development of urban areas. Because of theknowledge level limitations and planning restraints, as the growth of the urbantransportation demands evolve, unreasonable layouts and establishment of expresswayentrances and exits gradually change a city’s road network traffic development into abottleneck. In order to improve the scientific and reasonability of the design for theexpressway entrance and exit, research has been performed on the Chongqingexpressway new entrance infrastructure. The research contents are as followed:①In light of traffic equilibrium theory, the joint structure analysis and thedistributed traffic research on the expressway node and the related city road have beencalculated; a distributed traffic model on expressway node and its connecting roadnetwork has been established. With the OD network traceback technology and thedistributed model of the expressway network, we are able to calculate the equilibriumtraffic flow, analyze and search the areas not qualified for the equilibrium condition, andmake a general instruction for the expressway ingress location.②Based on the interchange elements research, the interchange distance isdivided into three parts: acceleration lane length, interchange spacing, and decelerationlane length. Through the element analysis of all lane lengths, the minimum spacingmodel is improved in terms of integrated ramp mode, traffic flow, vehicle speed onmain road and double lane ramp.③By using the calculation formula of the interchange spacing component length,the mathematical model that contains traffic flow, vehicle speed, and the interchangespace has been established. Based on this mathematic model, we are able to calculateand study the minimum spacing value between ingress and egress (Chongqinginner-road expressway: double way with six lanes and ramp with two lanes) whilecomparing different combined ramp models, different car speeds and different trafficflows. We are also able to analyze the relationship of ramp form, ramp width anddifferent traffic flow, which is the basis of ramp establishment. ④To use Chongqing inner-ring as expressway an example, this essay incorporatesan integrated overview of all aspects of these problems and conditions and analyzessuch conditions in both general terms and specific details. Under the traffic equilibriumassumption we are able to identify the systematic defects of the expressway networkand how they coincide with the different supply and demand needs. The resultantsolution is identified demonstrating a clear need for additional entrances to theexpressway system. This study analyzes in detail the ingress/egress needs of theexpressway within a control strategy, for current and future needs and makesrecommendations with revised ingress/egress locations. This research is done to ensurethat the expressway network improves its general capacity through integration betweenexpressway and other roads, which balances and combines both theoretical needs andpractical application solutions.