Traffic Optimum Design of a T-Type Roundabout-A Case Study

Congestion at an intersection has a traffic impact on road network capacity. This paper analyzes the current situation of the T-type roundabout of Tanan Road and Jiefang Road in Jiaozuo City, and finds that the intersection has a low capacity, a large delay and complexity indicators. Therefore, it is necessary to optimize the traffic design of the intersection. In this paper, the channelization is redesigned and the signal control is added. The position of the crosswalk is set near the intersection. The phase design method is used to coordinate the passage between the persons and the vehicles, and a turning lane is added to release the turning vehicle. It is calculated that the total capacity of the newly designed intersection is increased from 4554pcu/h to 5797pcu/h, and the average delay of each entrance is reduced from 53s to 32s; the intersection complexity index is reduced from 44 to 11. The traffic capacity and safety level of the intersection have been improved, and it has a certain reference significance for similar intersection design.