A Traffic Behavior Research On Diamond Interchange Exit Of Urban Expressway

Urban expressways are kind of road system for automobile fast driving and become more and more important in urban traffic network system. Expressway system includes main road lanes, exits and ramps. Exit always become the bottleneck of the expressway system, so it is necessary to find efficient way to increase the capacity of exit. At present, so much research has been done much on merge and diverge areas of interurban expressways. There is little research about exits and waving areas of urban expressways has been done. The study in this paper will give some advice to guide further study on exit considering waving areas of urban expressways. In this paper, analysis about traffic characteristic of exit and waving areas of urban expressways has been done firstly. Then on the base of field survey data, micro-simulation software-VISSIM is calibrated and validated. In the end the model about exit on diamond interchange of Urban Expressway was setup. In the simulation test, we found the length of extra lane and divide line, the rate of bus and bicycle driving behavior on supplement road, the length of waving area have different affect on diamond interchange exits of Urban Expressway. At last, it suggests 100 meters long for extra lane of exit, 20 meters long for divide line and 150-300 meters long for waving area.