Car Following Behavior under Foggy Conditions with Different Road Alignments — A Driving Simulator Based Study

Abstract

The aim of this study was to investigate the change of driver's car following behavior under foggy conditions with different road alignments. Based on the 8degree-of-freedom high-fidelity driving simulator of Tongji University, this study constructed four experimental scenarios, which were clear weather, 100m-visibility, 60m-visibility, and 40m-visibility. In each experimental scenario, four road alignments (straight line segment(SL), curve segment(CS), sloped straight line segment(SS) and sloped curve segment(SC)) were carried to make a contrast. Twenty-eight participants took part in driving simulation experiments. The variables including headway distance, headway time and lane deviation were collected to characterize longitudinal and lateral car-following stability. The results showed that the headway distance and headway time corresponding to the four road alignments had a downward trend with the decrease of visibility, especially on the SC. Under the same visibility conditions, there was a significant difference in minimum headway distance and minimum headway time among the four different road alignments. Besides, the minimum headway distance and minimum headway time on the SS and SC were obviously higher than that on the SL and CS. Furthermore, except for the visibility of 40m, there was a significant difference in the maximum lane deviation corresponding to the four road alignments under other three visibility levels, and the maximum lane deviation on the SC were higher than that on the other three road alignments.