Want to drive for FedEx, UPS, or Old Dominion? You need the "T" endorsement. The CDL Doubles and Triples Practice Test covers the physics of pulling multiple trailers.
Unlock LTL Jobs and Home-Daily Runs
Average Salary at Major Carriers
Pull two trailers, double your value. LTL (Less-Than-Truckload) carriers require the T Endorsement.
Often with excellent benefits. Most doubles/triples routes are regional with daily home time.
Less touch freight. Great for drivers who prefer consistent schedules over handling cargo.
Passing Score
Questions
Endorsement Code
Master these critical topics for the T endorsement exam
A converter dolly is the coupling device of one or two axles and a fifth wheel that allows you to couple a second semitrailer to the rear of a tractor-trailer.
60% of students fail because of this. You must know which valves to open to let air flow to the rear.
| Location | Shut-off Valve Status |
|---|---|
| Rear of Front Trailer | OPEN (Let air back) |
| Rear of Dolly | OPEN (Let air to rear trailer) |
| Rear of Last Trailer | CLOSED (Hold pressure) |
One of the most important concepts on the T endorsement exam
Rear trailers amplify the movement of the tractor. A 5-foot lane change by the tractor can result in a 15-foot swing by the rear trailer.
The heaviest trailer must always be in the lead position (closest to the tractor). The lightest trailer goes in the rear. This prevents the "crack-the-whip" effect.
"Got hired by FedEx Ground! The 'Crack-the-Whip' questions on this site were exactly what I saw on the DMV exam."
"Understanding the air valve logic was hard until I saw the table on this page. Passed with 100% score."
Everything you need to know about the Doubles & Triples (T) endorsement
It is considered moderately difficult. The main challenge is understanding the specific air brake connections and the physics of "crack-the-whip".
No. In most states, the CDL Doubles and Triples Practice Test prepares you for a written knowledge exam only (20 questions). However, your employer will likely require a road test.
Generally, no. It is nearly impossible to back up doubles or triples straight. You must plan your route to avoid backing. If stuck, you usually have to uncouple and back units separately.
The heaviest trailer must always be in the lead position (closest to the tractor). The lightest trailer goes in the rear. This prevents the "crack-the-whip" effect.
Most states have 20 questions. You typically need 80% (16 correct answers) to pass.
Master the "Crack-the-Whip" effect and air valve logic with our CDL Doubles and Triples Practice Test.
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