New Methodology for Defining Level of Service at Toll Plazas

Abstract

Numerous measures of effectiveness are available to evaluate a toll facility for its level of service including density, volume-to-capacity ratio, and delay. Based on field research and data analyses, delay is recommended to be the most credible measure of effectiveness for evaluating the level of service at a toll plaza. More specifically, the 85th percentile of the cumulative individual vehicular delays was found to capture the delay with better precision. An extensive database of traffic analyses for two mainline toll plazas in Orlando, Florida, representing different plaza configurations and various levels of electronic toll collection usage, was used to validate the methodology. There were 37,175 individual vehicle records used from actual field data and simulation runs from the Toll Plaza Simulation Model TPSIM. Service time was examined to determine the level a driver begins to feel discomfort and inconvenience at a toll plaza. A level of service hierarchy was established based on the conclusions of this analysis, feedback from professionals, and reference to the U.S. Highway Capacity Manual.