Traffic simulation of continuous flow intersection with displaced left-turn: a case study

Today, our community is facing a growing numbers of transportation challenges, as traffic grows and congestion worsens for signalized intersections. Based on that its needed balances solutions that improve safety and keep mobility for users with minimum travel time. The objective of this research is to investigate the implementation of continuous flow intersection with displaced left turn with developed simulation traffic model by VISSIM program to evaluate the traffic operation impacts of displaced left turn on performance of signalized intersection in terms of vehicle delay, length of queue, and stopped delay. This research studied congested signalized intersections in Baghdad City. An innovative solution of continuous flow intersection with displaced left turn was implemented to alleviate congestion and high vehicle delay. The displaced left turn DLT reduced the average vehicle delay about 44% and improved the deterioration level of service from (F) to better level of service (D) for north and south approaches which represented the most congested legs of intersection during the peak period. The results of stopped delay for DLT intersection with developed signal timing were lowest than the conventional intersection by about 51% and 34% for south and north approaches respectively. This implies that DLT intersection reduced the extra stops of vehicle and improved the overall efficiency of signalized intersection. The reduction in the queue length ranged from 47.5 to 42%; otherwise conventional intersection showed long queue length and higher vehicle delay. Therefore, regarding queue length, DLT intersection with developed signal timings strategy had better performance for traffic operation than conventional intersection. © 2022, The Author(s).