Free DE CDL Double/Triple Trailers Practice Test 2025

What kinds of companies use double-trailer vehicles to haul loads? Nationwide (including Delaware), double-trailer trucks are commonly used in the logistics sector to haul freight between distribution hubs. LTL (Less-Than-Truckload) carriers and parcel delivery services also use double trailers. The retail and E-commerce sector employs double-trailer trucks to move goods from distribution hubs to stores, restaurants, and supermarkets. Additionally, in Delaware, the chemical industry uses double trailers for bulk transport of chemicals and plastics, the Delaware City Refinery uses doubles to transport fuel, and International Paper uses doubles to transport paper and packaging materials.

To drive combination vehicles, you must obtain a Class A CDL. First, you must pass the General Knowledge Test and a skills test to obtain any class of CDL. To get a Class A CDL, you must also pass the Combination Vehicles knowledge test on the theory of operating combination vehicles. And to drive combination vehicles with double trailers, you must also obtain a Double/Triple (T) endorsement on your Class A CDL. (Triple trailers are prohibited in Delaware.) To obtain this endorsement, you must pass the Double/Triple knowledge test.

All these knowledge tests are based on the official Delaware CDL manual (Delaware CDL Handbook 2025). You likely studied parts of this manual to get your CDL. The Double/Triple endorsement test is based on Chapter 7: Doubles and Triples. However, if you’re tired or daunted from studying that manual, we have a more effective approach we would like to share with you.

This Delaware Doubles and Triples Endorsement Practice Test, one of five we offer, supplements the official manual with intensive practice. It’s based on Chapter 7 of the official CDL manual, just like the official Double/Triple knowledge test. It’s up to date as of November, 2025. The 20 multiple-choice practice questions and answers on this practice test address such topics as air lines, converter dollies, coupling, following distance, rearward amplification, and rollovers.

Our AI Assistant can help you figure out the answer to 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 has no time limit; take all the time you need to learn and master the material covered by this practice test. Not satisfied with your final score? You can retake this practice test as often as you wish.