Influence of driver and vehicle attributes on operational characteristics of U-turning vehicles

Mid-block median openings (MBMOs) are provided to take a U-turn, which is a complex process. To make this movement a vehicle has to stop at the MBMO to find a suitable gap in the approaching through traffic stream. Two parameters, namely, service delay (SD) and occupancy time (OT) are crucial operational cha­racteristics of an MBMO, which significantly affect traffic operation. The present study examines the influence of driver behaviour and vehicle attributes on SD and OT at six-lane and four-lane divided roads. From statistical analysis, SD was observed to be less at low approaching through traffic volume (ATTV) compared to high ATTV, whereas OT was observed to be high at low ATTV, and it decreased with increase in ATTV. Male drivers showed aggressive driving behaviour compared to female drivers, and the same was validated using a two-tailed t-test. Moreover, personal vehi­cles were found to behave defensively compared to commercial vehicles. Also, loaded vehicles were obser­ved to turn their steering slowly being concerned about the safety of their passengers and goods compared to empty vehicles. The findings of this study will be beneficial in validating simulation results, defining level of service, etc. for planners in regulating the traffic efficiently.