An Analysis of HOV Lanes

High occupancy vehicle (HOV) lanes are freeway lanes reserved for vehicles with more than a predetermined number of occupants. HOV lanes can affect the capacity of a freeway through both an underutilization effect and a disruption effect caused by lane-changes. This book examines the physics of HOV lanes and their overall impact on traffic. It uses a simple car-following model with lane-changing that matches field data with considerable accuracy. Current models of this type have usually a large number of parameters, many of them unobservable and/or with no physical meaning. This one, in contrast, requires few parameters and is based only on physical principles. It uses simple microscopic rules to reproduce the aggregate characteristics of traffic. The movement of a vehicle is only constrained by its mechanical properties, driver comfort, and safety. The model is used in micro-simulations to test simple strategies for increasing the efficiency of HOV lanes and reducing the disruptions they cause. The results and their implications are useful to transportation professionals and academicians, especially those developing new methods to improve traffic flow.