Development of Managed-Lane Access Guidelines Based on Gap Acceptance Theory

Abstract

One strategy for improving freeway performance is implementation of managed lanes (MLs). Vehicles access an ML located in the freeway median by weaving across the general purpose lanes (GPLs) and entering the ML from the leftmost lane of the GPLs. Such intense lane-changing maneuvers cause traffic turbulence, which induces special operational problems with capacity, level of service, and safety. The principal objective of this research is to develop design guidelines for the ML access (or exit) spacing between the entrance (or exit) ramp and the ML access opening and for the ML access opening length. This research develops analytical weaving models based on gap acceptance theory; the models estimate the probability of successful weaves in these weaving distances. The research also develops design guidelines for these distances on the basis of the analytical weaving models.