Identification of Effective Intersection Control Strategies During Peak Hours

Abstract

Traffic congestion during peak hours is one of the major issues in developing countries like Sri Lanka. Drivers undergo a considerable delay during the peak hours especially in the city centres. There are several identified reasons for the congestion. Among them ineffective intersection control strategy used is one of the major causes. There are several levels of intersection controls available. In case of Sri Lanka during the peak hours most of the intersections in city centres are controlled by traffic police in major intersections and in some extreme traffic conditions grade separated intersections also provided. When the traffic police officers control the intersection, they mostly use the queue clearing approach. In such case their preference will be on the major road movements and lesser preference will be given to the minor road movements. This study tried to find out the effectiveness of the manual control by traffic police officers compare to traffic signals. Four Junctions which are controlled by Traffic police officers during the peak hours selected for the analysis. Traffic micro simulation software VISSIM has been used for the analysis and it has been calibrated and validated to local conditions before using it for the analysis. Junctions were modelled for the traffic police phase arrangement and cycle time, and for a designed traffic signal time. When the junction is undersaturated traffic signals gives lesser delay than traffic police officers control. When the junction is oversaturated traffic police officers become effective because they allow risky merging movements to reduce the critical flows.