Free HI CDL Double/Triple Trailers Practice Test 2025

In Hawaii, the use of double trailers is effectively restricted, and triple trailers are not allowed at all. A typical “pup” trailer is about 28 feet long, so two of them have a combined length of 56 feet (not counting the connecting dolly). In HI, however, the maximum allowed length of the semi-trailer part of a truck is just 48 feet unless an oversize permit is obtained. For this reason, if you want to pull doubles (or even triples) in your trucking career, you may find more employment or economic opportunities outside the state.

To drive combination vehicles, you must obtain a Class A CDL. First, you must pass the General Knowledge Test on general commercial driving theory and a skills test to obtain any class of CDL. To get a Class A CDL in particular, you must also pass the Combination Vehicles knowledge test on the theory of operating combination vehicles and pass the skills test in such a vehicle. Under federal regulations, to drive combination vehicles with two or even three trailers or semi-trailers, you must also obtain a Double/Triple (T) endorsement on your Class A CDL. (However, triple trailers are prohibited in Hawaii.) To obtain this endorsement, you must pass the Double/Triple knowledge test. (No skills test is required for this endorsement.)

All these knowledge tests are based on the official Hawaii CDL manual (Hawaii CDL Handbook 2025). You likely studied parts of this manual to get your CDL. All questions on the Double/Triple knowledge test are based on Chapter 7: Doubles and Triples.

We have created a set of study tools to help aspiring drivers like you pass their knowledge exams on their first try. This Hawaii 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 March 2025. The 20 multiple-choice practice questions and answers on this practice test deal with 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. You won’t have to wait till the end of the test to learn why your answer was incorrect.