Improvement of traffic control at intersection sites

Abstract

There is a frequent need for conducting an evaluation to upgrade mobility and safety at intersections. The study goal is to; examine the suitable type of control, demonstrate a typical scenario for evaluation task, and achieve suitable alternatives that solve problems of congestion and their consequences. The optimized choice with a design of traffic operation as well as the geometric layout, are proposed for each studied site. Five individual intersections were studied within Babylon province in Iraq. Three methods are adopted due to; Institute of Highway Transportation IHT, Department of Transportation DoT and Iraqi Highway Design Manual SORB, to identify the suitable control. SYNCHRO 10 software is used for analyzing operational performance for existing conditions and suggested alternatives. Due to SYNCHRO 10, most intersections operate at an unacceptable level of service. Converting the Station and Al-Irjoan intersections from TWSC type to roundabout type decreased the average delay about 97% and 95% respectively. For the signal intersections, Al-Salam and Awlad-Muslim, the indirect left turn is the best alternative with a decrease in delay by about 91% and 92% respectively. For Al-Sadah intersection, installation of a traffic signal instead of AWSC type decreased the delay about 82%. Thereby level of service raised from F to B in; The Station intersection, Al-Salam intersection and Al-Irjoan intersection. LOS also raised from D to A in Awald- Muslim intersection and from F to C in Al-Sadah intersection.