Red and amber lights on the rear of the trailer must be:
Correct. Brake lights, turn signals, marker lights, and reflectors at the rear must be operational and clean. Damaged or non-working lights are an out-of-service item.
CDL Practice Question #209
Category: Combination Vehicles
Why this question matters
This question is one of 55 in our Combination Vehicles bank. The reasoning above comes directly from the AAMVA CDL Manual, the source document used by every U.S. state DMV. Memorizing the underlying rule — not just the letter answer — is what separates passing on the first attempt from a return trip and another fee.