Modeling overtaking distance and time along two-lane undivided rural highways in mixed traffic condition

Overtaking in a two-lane rural highway is a critical maneuver for safety and operations. This paper presents overtaking distance and time models for mixed traffic based on 117 accelerative overtaking maneuvers by 28 drivers. A passenger car (PC) fitted with GPS and cameras was used to record the overtaking maneuvers while passing motorized three-wheelers, PCs, light commercial vehicles, and heavy vehicles (HVs). Speeds of overtaking and overtaken vehicles, inter-vehicular gaps maintained before and after overtaking, and the effect of vehicle types were considered for developing the models. The distance and time required to overtake an HV were found to be the highest. The longitudinal gaps and speed differences between overtaken and overtaking vehicles observed in this study were lesser than the one reported in the published literature. A comparison with geometric design guidelines revealed the need for further review of the overtaking distance considered in designing two-lane undivided Indian highways.