Variable message sign (VMS) seems to be a good way for traffic information releasing in fog weather because of active luminous. However, it is still not quite clear whether the normal text height displayed on VMS can meet drivers’ visual requirements under fog weather. A total of 33 participants were recruited to test the effects of text height on drivers’ visual characteristic by dynamic driving simulation experiments. Comparison results showed that the distance between driver reading finish point and VMS (DRFV) increased significantly as the text height increasing for both normal and fog conditions. Under the fog conditions, DRFV and visual cognition time were slightly better. Vehicle speed at reading finish point and driver subjective evaluation score for VMS under these two weather conditions were not found significant difference. Drivers tended to slow down in advance to compensate for reduced visibility in fog conditions.

CICTP