Investigation of performance and lane utilization within a passing lane on a two-lane rural highway

Abstract

An investigation into platooning and passing maneuvers within a passing lane section on a rural two-lane, two-way highway was considered in this study. The study site was located on US Highway 287 between the town of Townsend and the City of Helena in the state of Montana. Traffic volumes at study site, while considered relatively low, were typical on two-lane highways in many rural states. Per-lane analysis of performance measures and lane utilization (volume split) were used to indirectly examine passing maneuvers and lane changing at successive locations within the passing lane section. For the case study site, it was evident that traffic performance became relatively stable beyond half a mile into the passing lane for the traffic volumes investigated. Therefore, results strongly suggested that most passing maneuvers already took place before the 0.5-mile station and that the actual passing lane length was well beyond the optimal length required for breaking up platoons and improving performance.