The operator of any vehicle required by section 60-6,235 to have clearance lights shall, immediately upon bringing his or her vehicle to a stop upon or immediately adjacent to the traveled portion of the highway at any time during the period from sunset to sunrise, (1) place one lighted flare or one red emergency reflector at the side of such vehicle just inside the white line marking the center of paved highways and near the center of dirt or gravel highways, (2) place one lighted flare or one red emergency reflector approximately one hundred feet to the rear of such vehicle, and (3) place one lighted flare or one red emergency reflector approximately one hundred feet to the front of such vehicle. The operator shall maintain such lighted flares or red emergency reflectors in such positions during the time such vehicle remains parked, except that motor vehicles transporting flammables shall be required to use two flares or two red emergency reflectors to be placed as described in this section to the front and rear but shall not be permitted to place open flame flares adjacent to such vehicles.