Implementing Active Traffic Management Strategies in the U.S.

Limited public funding for roadway expansion and improvement projects, coupled with continued growth in travel along congested urban freeway corridors, creates a pressing need for innovative congestion management approaches. Strategies to address congestion have been implemented in many areas of this country and include such options as variable message signs, High Occupancy Vehicle (HOV) lanes, toll lanes, ramp metering, and network surveillance. These strategies, however, have largely been deployed so that they function independently and are often implemented only on preset schedules or manually in response to an incident. Active Traffic Management (ATM) utilizes many of these same strategies but does so in concert in order to maximize the efficiency of transportation facilities during all periods of the day and under both recurrent and non-recurrent congestion conditions. This approach stresses automation to dynamically deploy strategies to quickly optimize performance and enhance throughput and safety. There are many opportunities and challenges associated with the implementation of ATM in the U.S. To gain a better understanding of the issues related to the potential deployment of ATM strategies, this study focuses on the following: (1) Assessment of the state of the practice for ATM strategies, such as speed harmonization, temporary shoulder lane use, and junction control; and (2) Analysis of potential operational benefits from implementing temporary shoulder lane use strategies on a segment of I-65 in the Birmingham, AL region. The study uses microscopic simulation modeling to quantify the impacts of temporary shoulder lane use on traffic operations. Moreover, a detailed cost-benefit analysis was performed to analyze the economic feasibility and potential gains from deployment. The analyses showed significant operational, environmental, and economic benefits from the potential temporary use of the left shoulder lane within an ATM environment. These results clearly indicate the excellent potential of temporary shoulder lane use as an ATM tool for addressing recurrent and non-recurrent congestion along I-65, in the Birmingham region. The study also summarizes best practices along with recommendations for advancing the research and implementation of active management strategies.