Managed Lanes: Current Status and Future Opportunities

The continuous increase in automobile use is directly related to the increase in congestion and decline in air quality in urban settings. In response to this reality, transportation agencies across the nation employ a number of strategies to reduce traffic demand or spread it over time and space. This can be done by using lane management strategies that regulate demand, separate traffic streams to reduce turbulence, and utilize available and unused capacity. In recent years, application of such operational policies has evolved into the notion of lanes. This study examined the potential role of managed lane strategies in addressing traffic congestion issues in the Birmingham, Alabama metropolitan area. More specifically, the study first reviewed the state-of-practice on managed lanes and summarized best practices and lessons learned from earlier deployment efforts. Then an assessment of potential operational impact from implementation of High Occupancy Vehicle (HOV) and designated truck lanes along I-65 in Birmingham was performed. This was accomplished through detailed traffic simulation modeling using the VISTA mesoscopic tool. Alternatives considered included (a) the conversion of an existing lane into an HOV or truck designated lane and (b) the addition of a new HOV lane along the study corridor. A detailed sensitivity analysis was performed to determine the impact of various percentages of HOV and truck use on traffic operations. A comprehensive cost-benefit analysis was also performed to determine the most economically efficient alternative among all HOV options considered. The research findings from this study are expected to benefit both the scientific community and those agencies and authorities responsible for planning, designing, implementing, managing, and operating transportation facilities.