DESIGN OF TRAFFIC SIGNAL IN A FOUR LANE INTERSECTION: A CASE STUDY OF OPOLO ROUNDABOUT, YENAGOA BAYELSA STATE NIGERIA

Abstract

Traffic signals, also known as traffic lights, stop light and traffic control signals are signaling devices located at road intersections, pedestrian crossing, and other location to control conflicting flows of traffic. The increasing number of vehicles on the road intersection has given rise to many problems like road accidents, congestion and conflict. These problems can only be solved by designing proper traffic signals at intersection for continuous and smooth movement of vehicles. Yenagoa city is also facing the same problem. This research work presents the proper designing and stimulation of traffic signals at Opolo roundabout Yenagoa in Bayelsa state Nigeria. The research deals with the stimulation of design through the use of Webster’s method in carrying out the design and data collection involves using manual traffic volume count, with traffic survey route. The conversion of traffic count at the intersections to passenger car unit (PCU) for the design of traffic signal, it was observed that PCU obtained at the four intersections in the roundabout where 2480, 3172, 2382 and 821.Based on the calculations done on the PCU values obtained from the traffic survey, the optimum Signal Cycle Length was found to be 60 seconds. The cycle length at the existing intersection is same for three major roads, 189 seconds and for the minor road 259 seconds. The implementation of this design will therefore go a long way in the reduction of traffic congestions and delays around the Opolo roundabout.