Enhancement of the Traffic Operation Performance of Al-Mansour Signalized T-Intersection in Baghdad City

Abstract

The vehicles traffic volume has been increasing rapidly over last years in Iraq especially in central business districts (CBD) in Baghdad city. The increasing results in growing of congestion level, environmental pollution and time wasted during travel especially at the intersection points. The objectives of the study are evaluating the existing level of service (LOS) at Al-Mansour signalized T-intersection in Baghdad city and improving traffic performance by estimating the best alternatives to increase the traffic capacity of intersection. The traffic volume data were collected manually by group of engineers based on traffic operation of policeman. Assessment of existing intersection at study area is considered using HCS software (2010), also AutoCAD (2017) for display of all existing and proposal layouts. Study results showed that Al-Mansour Intersection currently behaves serious deterioration causing forced conditions LOS "F" with delay of 221.6 s/veh, therefore; instantaneous solutions is to be considered concerning the upgrading of serviceability based on trying many proposals considering the signal timing and geometrical changes with required number of lanes and phases. It showed that a suitable choice is to construct a tunnel (1 lane / direction) along 14-Ramadhan street with actuating two phases giving LOS "B" and delay of 11.1 s/veh.