Can a snow plow blow a car off the road? They used an old plow and increased the size of the plow blade to create more air pressure, (wall of air). A real snow plow is pushing a wall of snow/ice in excess of six feet tall at an average speed of 45-55 mph (highway). I have seen instances of a car being blown off the road let alone a person. The myth was done incorrectly. Air pressure (wall of air) alone will not blow a car off the road.