Free ND CDL Double/Triple Trailers Practice Test 2025

If you want to pull doubles or triples for a living, you should be glad you’re living in North Dakota. Double Pup trailers are legal nationwide, but North Dakota also allows other types of Long Combination Vehicles (LCVs) on officially designated routes: Rocky Mountain Double, Turnpike Double, and Triple. (However, you may need an oversize permit if your vehicle exceeds the state’s length or weight limits.) Several of the state’s key economic sectors use Doubles or Triples for transport.

In much of the nation (including North Dakota), the logistics and freight sector makes heavy use of double trailers for efficient transport. In North Dakota, several companies, including FedEx Freight and UPS, use double trailers for cross-border shipping to or from Canada. In this state, these two companies also use triples for parcel delivery. Retailers like Walmart and PepsiCo use double trailers to transport products to stores and warehouses. Marathon Petroleum uses double tanker trailers to transport crude oil. The agriculture sector uses doubles to transport bulk grain, livestock feed, flour, processed sugar, and fertilizer.

To legally pull doubles or triples, you must hold a Class A CDL, be qualified to operate air brakes, and obtain a Double/Triple (T) endorsement on the CDL. To get this endorsement, you must pass the Double/Triple knowledge test. This test covers such topics as safe handling, air brakes on doubles and triples, coupling and uncoupling, emergency situations, pre-trip inspections, and state and federal regulations on doubles and triples. (No special skills test is required for this endorsement.)

This knowledge test is based on the official North Dakota CDL manual (North Dakota CDL Handbook 2025), especially Chapter 7: Doubles and Triples. We can help you pass the knowledge test on your first try – something you can’t guarantee just by reading the manual.

This North Dakota 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 May 2025. The 20 multiple-choice practice questions and answers on this practice test deal with air lines, converter dollies, coupling, emergency situations, following distance, and rearward amplification.

Our AI Assistant can give you a hint or further elaboration if you get stuck on a question or an immediate explanation of the correct answer if you still miss the question. You can also ask your own questions about driving.

This practice test isn’t timed; take all the time you want. Disappointed with your final score? You can retake this practice test as often as you wish.

Be sure to try our other four North Dakota Doubles and Triples Endorsement Practice Tests too!