Traffic Design at Urban Street Intersection Connecting Expressway Ramp Terminal

This paper addressed the traffic design methods of urban interchanges taking the interchange of Wanbao arterial and the 2nd ring urban expressway in Changsha as an example. Interchange was firstly designed by adjusting the functions of lanes and channelizing internal space of the intersection. Then, through overlapping phases and adjusting phase sequences, an optimal signal design was made to the interchange. At last, the design was evaluated and analyzed based on comparisons of capacity, saturation and delay indexes. The results showed that capacity of the interchange increased by 21.68%, saturation reduced by 27.5% and average delay reduced by 40.68%. In addition, the interweave between ramps flow and street flow was almost eliminated. The operational efficiency was obviously improved.