Driver Heterogeneity in Rubbernecking Behaviour at an Incident Site

Incidents can reduce roadway capacity due to lanes blockages, and in some cases, also affect the flow in non-incident direction. This paper provides insights into change of driving behaviour while passing an incident site in attempt to assess rubbernecking activity. We use empirical trajectory data obtained from a helicopter-mounted video camera. By assessing the points where acceleration changes on speeds profiles over distance of individual vehicle, the behavioural changes of driver passing in the opposite direction of the freeway incident can be determined. Results show that the variations in speed in the upstream of incident location are substantially higher within passenger car drivers then within the truck drivers. The passenger cars in the median lane reduce the speed further upstream, mostly with sharp deceleration while passenger cars in the shoulder lane reduce the speed closer to the incident scene. Truck drivers, on the other hand, tend to decelerate earlier and farther upstream, more than 125 m from the incident site. Some drivers did not exhibit rubbernecking behavior, passing the incident with a steady speed. This study emphasizes the difference between passenger car and truck driving behaviour while passing an incident location. The results provide a better understanding of rubbernecking behaviour and useful for modeling driver behaviour under incident conditions.