Evaluation of a Signalized Intersection with Hook Turns under Traffic Actuated Control Circumstance

Right-turning vehicles (in countries where vehicles driving on the left-hand-side of the road, e.g., UK, Australia) have large impacts to the operation of intersections. This paper focuses on a traffic maneuver for right-turning vehicles, named the hook turn (HT), which has been successfully implemented in Melbourne for over 50 years. To fully assess the operational performance of the intersection with the HT, two similar intersections are established by a computer model. One intersection plan has the HT maneuver, named the HT plan, and the other one has no HT maneuver, named the traditional plan. Both plans adopt the actuated control method (ACM) for signal settings. For the HT plan, a strategy is developed to cope with the spillover of HT vehicles using the loop detector data; dynamic adjustment of minimum green times is incorporated. With different traffic volumes and vehicle ratios, 24 simulation scenarios are designed. Two classes of indices, average delay and number of vehicles crossing the intersection per hour, are used to assess the performance of the two plans. The simulation results show that the HT plan can only reduce the average delay of through vehicles when the total intersection volume and the ratio of right-turning vehicles are high, and the vehicle capacity of the HT plan is, in general, greater than that of the traditional plan in most scenarios.