A Review for Signal Coordination at Congested Intersection

Abstract

The urban traffic congestion has become a global phenomenon. Rapid urbanization and industrialization have caused drastically growth of vehicles all over the world. But the problems like congestion, delay, energy consumption, environmental pollution, etc. still remain in question if the traffic signals are not coordinated. Coordination of signals is achieved when the flow of traffic on a given phase of movement at one intersection is accommodated by a ―go’’ phase on its arrival at the next signalized intersection. It enhances progressive movement of traffic streams at some specific speed without enforced halts and reduced overall delay. It reduces the speed variations and provides smooth traffic operation, which increases capacity, decreases energy consumption and reduces air and noise pollution. Goal of signal coordination is to get the greatest number of vehicles through the system with the fewest stops in a comfortable manner. At present, traffic volumes are higher during peak hours in all the approaches of the signalized intersections, i.e. on the major and minor streets. Therefore, it is necessary to coordinate the signals of the network in all the directions, rather than to coordinate on a single corridor. Considering this fact, a methodology has been developed for the pre-timed signal coordination at network level.