If a semitrailer must be parked on the shoulder of a roadway where the view is obstructed, and flags are being used in the place of lighted lamps, the flags should be placed:

If a commercial motor vehicle must be parked on the shoulder of a roadway where the view is obstructed, and flags are being used in the place of lighted lamps, the flags should be placed both in front of and behind the vehicle. The flag in the front should be 100 feet away from the vehicle, and the flag to the rear should be between 100 and 500 feet away from the vehicle.