EVALUATION OF A FUZZY LOGIC RAMP METERING ALGORITHM: A COMPARATIVE STUDY AMONG THREE RAMP METERING ALGORITHMS USED IN THE GREATER SEATTLE AREA

Abstract

A fuzzy logic ramp metering algorithm was implemented on 126 ramps in the greater Seattle area. Two multiple-ramp study sites were evaluated by comparing the fuzzy logic controller (FLC) to the other two ramp metering algorithms in operation at those sites over a four-month period. At the first study site, the days when the FLC was metering had lower mainline occupancies and higher throughput volumes in comparison to the days when the local algorithm was metering. At the second study site, the days when the FLC was metering had mainline occupancies that were similar, queues that were shorter, and throughput that was similar to the days when the bottleneck algorithm was metering.