The Department of Transportation with respect to state highways may place signs prohibiting or restricting the stopping, standing or parking of vehicles on any highway where, in its judgment, such stopping, standing or parking is deemed by the Department of Transportation to be hazardous to those using the highway or where the stopping, standing or parking of vehicles would unduly interfere with the free movement of traffic thereon. Such signs shall be official signs and no person shall stop, stand or park any vehicle in violation of the restrictions stated on such signs.