Evaluation of the Number of Conflict Points and Performance of Roundabout Case Study: Santitham Roundabout Chiang Mai Province

Abstract

Roundabout intersections are used generally in Thailand and other countries. It helps decrease the conflict points when compared with other types of intersections and helps reduce the speed of vehicles entering the roundabout. The objective of this study is to evaluate the conflict points with a high risk in accidents, and the operational performance of the existing and the alternative designs. In this study, Santitham roundabout in Chiang Mai was used as the study case and simulated in a traffic microsimulation. Three different intersection alternatives include: 1) the exiting condition, 2) increasing the diameter of the center island, and 3) increasing the diameter of the center island and redesigning the entry lanes. Results from the evaluation revealed that the number of conflicts point in the case of expanding center island size and improving the entry lanes were fewer than the other cases and was able to improve the overall operational performance of the roundabout.