The Integration Of Urban Expressway Traffic Organization And Control Research

In recent years, with the promoting of the city function, the expanding gradually of the city scale, the popularity of private cars and other factors, it makes the traffic demand increase sharply, and causes the phenomenon of the contradiction of the traffic supply and demand increasing highlighted, the more severe traffic pressure growing with each passing day. Although many cities alleviate the traffic problem by constructing the expressways, but the effect is not obviously, because the design of spatial location on and off ramp, which could make the queue vehicles on the ramp affect the traffic flow of the adjacent intersection, thus affect the normal traffic operation of the main line of the elevated road and at-grade road, and when the grade road has traffic jams, the elevated road which has the presence of excess capacity can not be used, and vice versa. So when it improves traffic by increasing the traffic infrastructure, at the same time, it also enlarges the area of traffic improvement, along with the space-time development, the traffic efficiency of the whole road network could gradually decrease, and mutual interference could be gradually seriously. For the overall organization and control of the city traffic, it should optimum control not only to a junction, section to solve the traffic problems, especially after the construction of expressways, it must optimize the whole urban expressway by the integration of traffic organization and control.This paper studied on the expressway, it was not only elevated road, but also at grade road and the surrounding road network covered by elevated road. According to the traffic problems in the expressway network, the domestic and foreign scholars came up with the adaptation models, methods and suggestions, from the design, traffic organization, traffic control and other aspects, to play a role in improving the traffic, but the actual application process is more difficult, and it was a lack of integration research in traffic organization and traffic control, as well as a lack of influence factors for the whole urban expressway, and a lack of systematic and comprehensive study. Therefore it was analyzed to traffic conditions, which was from Jinxing overpass to Juhua overpass of Kunming Main City No.2Ring Express System, for factors in the aspects of the land use, road conditions, traffic volume and composition, traffic conflict. Then, it was researched of the systematic expansion of the methods of traffic organization and control to urban expressway in three aspects:the at-grade road, the elevated road, the joint area up and down ramp, the process was established in the intersection of traffic organization and control, the improvement methods was put forward to each road section and elevated road. On the basis of previous studies, it was built the coordination control model of up ramp and its adjacent intersections, and the mathematical model of the minimum and maximum values of the variable lane in the joining area of down ramp and its adjacent intersections, the variable lane and the signal control projects was optimization designed.Finally, this paper took the section from Jinxing overpass to Juhua overpass of Kunming Main City No.2Ring Express System as an example, simulation software TransModeler was used to analysis of performance before and after taking measures of traffic organization and control, and indexes of vehicle for average delay and average queue length was selected to evaluate the overpass and the entire road network, and prove the measures of traffic organization and control to urban expressway scientific validity, for the future, the measures was applied to provide a systematic scientific basis for the optimization and regulation of urban expressway network.