Abstract: This disclosure pertains to a vehicular safety device utilizing a fog sensing apparatus for detecting the presence of fog immediately preceding the foremost portions of the vehicle. When fog is detected, the braking system of the vehicle is gradually but forceably brought into play reducing the speed of the vehicle to a preset maximum determined by a governor operated by the engine. A control unit is concurrently activated which causes the rearmost lamps of the vehicle to intermittently energize and automatically altering the mode of operation of the headlamps of the vehicle for a time period equal to the continual sensing of fog.