Development of Hierarchical Methodology for Benefit Evaluation of Vehicle-Highway Automation: Case Study of the Houston Katy Freeway

A hierarchical methodology used to design and benefit the evaluation of vehicle-highway automation systems at various levels of granularity is described. In this hierarchy, detailed microsimulation and experimental data and performance measures feed into consecutively higher, system-level analyses. Ultimately, top-level estimates of system benefits are provided to transportation decision makers. The method is designed to accommodate studies of autonomous vehicle control concepts such as the safety services under consideration as advanced vehicle control and safety system (AVCSS) intelligent transportation system services, some of which have been discussed as U.S. Department of Transportation Intelligent Vehicle Initiative services; it will also accommodate studies of the fully automated highway systems. The method is illustrated with a multifaceted set of studies of the relationship between the degree of automated vehicle-highway cooperation and system performance improvement on the Houston, Texas, Metropolitan Transit Authority High-Occupancy Vehicle facility on Interstate 10, also known as the Katy Freeway. The primary objective is to predict performance impacts for alternative concepts, which will undergo a major investment study, in a real-world setting. The study initially focused on automated highway systems, but the methodology has since been applied to the adaptive cruise control AVCSS service.