Managed Lanes: A Cross-Cutting Study

Increasing traffic congestion in the major metropolitan areas is costing billions of dollars each year in lost productivity, wasted fuel, increasing air pollution and hours of delay. Adding new general-purpose lanes is increasingly difficult because of factors such as construction costs, limited right-of-way, environmental and societal concerns. As a result, agencies are looking for solutions to improve the flow of traffic on existing facilities. One concept being considered is that of Managed lanes employ various strategies to improve flow and maximize the efficiency of the freeway system. Common types of managed lanes include high-occupancy vehicle (HOV) lanes, high-occupancy toll (HOT) lanes, value priced lanes, or exclusive or special use lanes. For the purposes of this study, managed lanes are defined as a limited number of lanes within an expressway cross section where multiple operating strategies are utilized, and actively adjusted as needed, for the purpose of achieving pre-defined performance objectives. The intent of the report is to review the state-of-the-art in managed lanes in order to increase the understanding of (1) what managed lanes are, (2) how to plan for implementation, (3) what operational and design issues are considered, and (4) how active management of the lanes over the life of the facility affect its implementation. This report describes operating managed lane projects through a case study approach, highlighting best practices of the projects the lessons learned. Emerging issues and knowledge gaps are also presented. The intent of the report is to provide a cross-cutting study of the issues and experiences of various agencies as managed lane projects are implemented and policies are drafted.