DELAY AND FUEL CONSUMPTION AT TRAFFIC SIGNALS

Abstract

A study which examined the trade-offs between fuel consumption and delay at signalized intersections revealed that savings of approximately one gallon per intersection per hour may be achieved without serious increases in delay. Greater fuel economy could be achieved, however, this would be very costly in terms of delay and would require significant changes in current attitudes toward the maximum reasonable waiting time at a traffic signal. Fuel consumption factors are discussed and techniques for estimating fuel consumption for any specific signal timing plan are outlined. The timing of isolated traffic signals for minimum fuel consumption utilizes a computer program, based on Webster's delay equation, to generate a set of cycle length and splits that will minimize fuel consumption for an isolated signalized intersection. The two best models used to estimate delay and stops in coordinated systems are TRANSYT and SIGOP-II which involve computer programs that use an iterative process to arrive at a set of solutions.