An Approach to Assessing Freeway Lane Management Hot Spots

Abstract

This research presents a procedure for capitalizing on the trade-off between urban freeway managed lanes and general purpose lanes that compete for limited road space. The basic goal of the procedure is to provide policy guidance for sharing any excess lane capacity on a timely and efficient basis. Potential operating policy options for these two types of lanes are categorized as “do nothing,” “lane management,” and “more than lane management.” The “lane management” condition recognizes the extent and duration of a “hot spot” as defined by underutilized managed lanes with congested general purpose lanes, or vice versa. Four major and three minor lane management hot spots are deterministically and stochastically captured along a 24-mi freeway stretch in California. The major hot spots account for 8.3% of the total time–space set. The approach, which can also be applied to predict upcoming hot spots, generates satisfying accuracy. Finally, strategies are proposed to prevent the hot spots, and the effects of lane management are estimated. The application of this approach is useful especially for managed lanes with limited access points that prohibit arbitrary lane changing.