Free SD CDL Double/Triple Trailers Practice Test 2025

Want to pull doubles or triples in your truck-driving career? If you’re a resident of South Dakota, we’ve got some good news: you’re living in a double- and triple-friendly state! Double pup trailers are legal nationwide. Furthermore, South Dakota also allows the following types of Long Combination Vehicles (LCVs) on designated routes (mainly I-29 and I-90): Rocky Mountain Doubles, Turnpike Doubles, and Triples. LCV drivers are in high demand because few drivers have the necessary endorsements and training to operate such vehicles.

If you want to drive LCVs, start by obtaining a Class A CDL. Obtaining the Air Brakes qualification is a practical necessity because virtually all LCVs have air brakes. Then pass the Double/Triple knowledge test to obtain a Double/Triple (T) endorsement on your Class A CDL. (No special skills test is required.)

After you obtain the Double/Triple endorsement, South Dakota also requires you to undergo specialized LCV training to operate LCVs (except for Double Pup vehicles). Once completed, you’ll receive an LCV Doubles Driver Training Certificate if you trained to operate Rocky Mountain Doubles or Turnpike Doubles, or an LCV Triples Driver Training Certificate if you trained to operate Triples.

The official Double/Triple knowledge test covers such topics as safe handling, air brakes on doubles and triples, coupling and uncoupling, rollovers, and trailer sway. This knowledge test is based on the official South Dakota CDL manual (South Dakota CDL Handbook 2025), especially Chapter 7: Doubles and Triples. You likely studied other chapters of this manual to pass the General Knowledge test and perhaps other knowledge tests too. But before you go back to the manual again to study for the Double/Triple endorsement, we would like to offer you a smarter approach. It supplements the manual to ensure you pass the Double/Triple knowledge test on your first try.

This South Dakota Doubles and Triples Endorsement Practice Test is based on the official CDL manual, just like the official Double/Triple knowledge test. It’s up to date as of September 2025. The 20 multiple-choice questions and answers on this practice test address such topics as air lines, converter dollies, coupling, following distance, rearward amplification, and rollovers.

If you need help answering a practice question, ask our AI Assistant 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. Disappointed with your final score? You can retake this practice test as often as you wish. Each time, the order of the questions will be randomized.