Abstract:In order to investigate drivers’ car following behaviors under hazy weather conditions, by using the high fidelity driving simulator with a motion system of 8 degrees of freedom, two scenarios, namely clear weather conditions and hazy weather conditions, were established to collect and analyze the key variables of car following behaviors including the time/distance headway, delay time and acceleration/deceleration rate at different car following stages under different traffic conditions. Compared to the clear weather conditions, the results indicate that hazy weather conditions have significant effects on drivers’ car following behaviors; the maximum distance headway significantly increases by 8.7%, 19.4%, and 25.6% under car following stages in case of freeflow conditions, congested conditions, and jam conditions, respectively. The minimum distance headway significantly increases by 13.0% under car following stage in case of freeflow conditions. The minimum time headway significantly decreases by 47.9%, and the mean value and the discreteness of the delay time significantly increases by 15.5% and 28.2% respectively, under car following stage in case of jam conditions. Drivers become more cautious in accelerating under hazy weather conditions. There exist significant differences in car following behavior at car following stages under different traffic conditions. With the increasing speeds, both the mean value and the discreteness of the maximum/minimum distance headway and the delay time increase significantly, while the time headway decreases followed by increasing afterwards.