The effect of fog on headway control
CAVALLO ; BEAUDOIN
Type de document
COMMUNICATION AVEC ACTES INTERNATIONAL (ACTI)
Langue
anglais
Auteur
CAVALLO ; BEAUDOIN
Résumé / Abstract
The hypothesis of headway overestimation in fog (Brown, 1970) has recently been corroborated by a series of fog chamber experiments. Participants under static viewing conditions overestimated vehicle distance by 30 to 60 % in foggy conditions, when only the vehicle’s lights remained visible (Cavallo, Colomb, & Doré, 2000). To validate these findings in a more ecological setting, we studied headway control in a driving simulator experiment. 30 participants carried out a car following task in normal and daytime fog conditions (visibility distance: 30 m). The speed of the lead car varied between 50 and 90 km/h. The participants were instructed to adopt a safe following distance and to adapt it according to the speed of the followed car. The results globally exhibited shorter temporal headways in foggy conditions. The amount of headway reduction was dependent on the adopted car following distance and the visual conditions associated with it. The findings confirm the occurrence of distance overestimation, as observed in earlier fog chamber experiments. They contribute to explain behavioural modifications when driving in fog.
