A CORSIM Testbed For Ramp Metering Algorithms

Ramp meters on freeways have been show to reduce system travel time, improve safety, and increase freeway capacities. This paper presents an effort to develop a simulation testbed for the evaluation of ramp metering algorithms using CORSIM’s Run-Time Extension (RTE), which provides exported functions and shared structures to communicate between the CORSIM microsimulator and the algorithms. The authors used a simulation network with 12 metered on-ramps for an 11-mile stretch of the I-95 corridor in Miami-Dade County, Florida to compare the results from three alternatives: fixed-time ramp metering control, Seattle fuzzy logic ramp-metering control, and no ramp metering. Results show that ramp meters are generally beneficial and that the Seattle fuzzy logic algorithm with only globally configured parameters outperforms a well-calibrated fixed-time control strategy, especially under congested conditions. The authors conclude that the simulation testbed developed in this research also makes possible the evaluation of additional ramp metering algorithms in a widely used simulation model in the United States.