Improving the Black Spot U-turn: A Case Study, In Front of Wing2 Royal Thai Airforce Lopburi Province

Abstract

This research aims to improve the Black Spot U-turn by time to collision (TTC). This study focuses on two types of U–turn that included U-turns with and without an exclusive lane. The study observed the traffic data on the route No.1 (Phahonyothin), under the supervision of the  Lopburi 1 highway district, department of highways. The experiments analyzed the Black Spot of U-turns from accident statistics. Geometric data and traffic parameters at the peak hours of the black spot u-turn were collected. The traffic conditions with and without exclusive U-turn lane were simulated with the microscopic simulation, named VISSIM. The results of time to collision (TTC) by the SSAM program were analyzed and compared. In this research, accident statistics during the year 2014-2016 were collected. It was found that9 accidents occurred at three U-turn located in front of Wing 2 Royal Thai Airforce due to improper distance.  The 1st U-turn has exclusive lane while 2ndand 3rd have no exclusive lanes. From simulation results, it was recommended that  the first U-turn has exclusive lane, the second U-turn should be closed and adding exclusive lane to the third U-turn.