Influence of Roadside Infrastructure on Driving Behavior: Driving Simulator Study

This paper describes the results of a driving simulator study that focused on the influence of roadside infrastructure on speed choice and lateral placement of car drivers. A review of the RISER detailed accident database revealed that lateral positioning and speed of the vehicle were two of the primary factors leading to crashes. The driving simulator study served as a means to include human factors principles into roadside infrastructure guidelines. Roadside features studied included trees, guardrails, barriers, panels, and emergency lanes. It was found that drivers tended to laterally move away from safety barriers when they first approached them, and they slightly slowed down. The type and size of a safety barrier appeared to be less important, only its presence had an effect. Trees were not found to affect the speed of the driver unless they were very close (2 m) to the road edge on an 80 km speed limit rural road and this effect faded rather quickly. There was no influence on speed if the trees were more than 4.5m from the lane edge. The fact that trees along the road are not considered to be a hazard, with drivers not adjusting their behavior, makes trees even more dangerous.