Evaluation of Coordinated and Local Ramp Metering Algorithms Using Microscopic Traffic Simulation
Joseph R Scariza, Tomer Toledo, Moshe E Ben-Akiva · 10th World Conference on Transport ResearchWorld Conference on Transport Research SocietyIstanbul Technical University · 2004
This paper evaluates four ramp metering algorithms at varying levels of complexity and sophistication. ALINEA is a local ramp metering algorithm. ALINEA/Q is an extension of ALINEA, which handles ramp queues in a more efficient manner. FLOW is a coordinated algorithm that keeps traffic at a predefined bottleneck below capacity. The Linked Algorithm is a coordinated algorithm that optimizes a linear-quadratic objective function. A generic network was created in MITSIMLab, and the effect of four variables was studied: total demand, ramp spacing, proportion of traffic using ramps, and traffic distribution among ramps. A regression analysis was performed on each algorithm to determine the sensitivity to each variable. The most significant result was that ramp metering, especially the coordinated algorithms, was only effective when the ramps are spaced closely together. It was also observed that ramp metering was only effective at relatively high demand, and that ALINEA/Q and the coordinated algorithms were more effective than ALINEA when the volume was extremely high.