Free NM CDL Double/Triple Trailers Practice Test 2025

Want to pull doubles in New Mexico? (The state does not allow triples.) You must obtain a Class A CDL (including passing the Combination knowledge test) and a Double/Triple (T) endorsement on your Class A CDL.

Is the T endorsement worth getting? Carriers tend to favor double and triple trailers (where legal) for improved transport efficiency. Yet not many truck drivers are qualified to pull multiple trailers. Those with the right qualifications are in high demand – and can earn significantly higher salaries. In New Mexico, as in much of the rest of the country, UPS Freight and FedEx Freight operate doubles for regional shipping. Wholesale and retail companies, like Albertsons & Smith’s and Walmart, deliver products in double trailers. Western Refining (now part of Marathon Petroleum) transports fuel in double tanker trailers.

To obtain the Double/Triple endorsement, you must pass the Double/Triple knowledge test. (No special skills test is required for this endorsement.) This test covers such topics as air brakes on doubles and triples, coupling and uncoupling, emergency situations, pre-trip inspections, safe handling, and state and federal regulations on doubles and triples.

This knowledge test is based on the official New Mexico CDL manual (New Mexico CDL Handbook 2025), especially Chapter 7: Doubles and Triples. However, you may have noticed this manual isn’t easy to learn. We can give you additional help to ensure you’ll pass this knowledge test on your first try.

This New Mexico Doubles and Triples Endorsement Practice Test, the first of five we offer, is based on the official CDL manual, just like the official Double/Triple knowledge test. It’s up to date as of October 2025. The 20 multiple-choice practice questions and answers on this practice test deal with air lines, converter dollies, coupling, following distance, rearward amplification, rollovers, and other topics.

Our AI Assistant can help you with any practice question. You can ask it to give you a hint or rephrase the question. You can also ask your own questions. If you still miss the question, the AI Assistant will immediately give you the correct answer and an accompanying explanation.

This practice test isn’t timed; take all the time you need to learn and master the material covered by this practice test. Disappointed by your final score? You can retake this practice test as often as you wish. Each time, the order of the questions will be randomized.

Be sure to try our other four New Mexico Doubles and Triples Endorsement Practice Tests too!