Frequently asked questions concerning the Motor Carrier Safety Assistance Program and commercial motor vehicles.
Does my trailer need working lights if you can still see the lights on my truck?
Yes.All required lamps must be operational on the rearmost vehicle in any combination (e.g., brake lights, taillights, turn signals, four-way flashers, clearance, identification, side marker, license plate lights). (49 CFR §393.9(a) and 393.11)

