Study of Overtaking Maneuvers on Wide One-Way Roads in Weak Lane-Disciplined Traffic Using Naturalistic Driving Data

Abstract

Drivers make assumptions and predictions on the expected paths of nearby vehicles. In traffic with weak lane discipline, prediction of the paths of other vehicles becomes more uncertain than in lane-based traffic because of frequent lateral wander. The situation becomes even more challenging on one-way roads where the scope for lateral wander is greater than on two-way roads. Study of overtaking maneuvers on wide one-way roads in the absence of lane discipline therefore becomes imperative. This paper investigates driver behavior while overtaking on wide one-way roads in disorderly traffic using naturalistic driving data collected by an instrumented vehicle. This study proposes definitions of the start and end of the maneuver that lead to behaviorally identifiable time points. The behavior of the overtaking vehicle driver is studied in both longitudinal and lateral directions. Data from 181 overtaking maneuvers on one-way roads of two different road widths are used to study the behavior. The primary observation of the present study is that, although the initial motivation for overtaking is a driver’s sense of urgency because the faster driver of the overtaking vehicle wants to avoid the slow-moving vehicle ahead, once the maneuver starts, the actions of the driver are guided by their concern for safety. One of the major implications of the present study is that the results can be used to develop microsimulation models to analyze driver behavior while overtaking in disorderly traffic streams.