What is the T endorsement?
Who uses the T endorsement
LTL carriers running pup trailers on linehaul, postal and parcel contractors, and drivers in western states where long combinations are common. Some of the best-paying linehaul jobs in the country require T because the freight moves as doubles.
Doubles versus triples
Doubles, two trailers, are legal in every state on designated routes. Triples, three trailers, are allowed only in about 17 mostly western states, often on specific highways and with length and weight limits. The T endorsement covers both; what you can actually pull depends on the state and the carrier.
What the test covers
The crack-the-whip effect and why the rear trailer rolls first, putting the heaviest trailer in front, the full coupling sequence with a converter dolly, uncoupling in the right order, the extra inspection items, checking that air reaches every trailer, shut-off valve positions, and driving adjustments: longer following distance, gentle steering, no quick lane changes.
How to prepare
Read the doubles and triples section of your state CDL manual, then work practice questions. The ELDT365 course lays the section out as short lessons with the practice questions in order, in English and Spanish, and gives you a certificate of completion.
Questions drivers ask
Does the T endorsement require a Class A?
Yes. Doubles and triples are combination vehicles, which is Class A.
Does T require ELDT?
No. The FMCSA ELDT rule does not cover the T or N endorsements. It is a knowledge test only.
How many questions is the doubles/triples test?
Typically 20, with 80 percent to pass. Exact counts vary by state.
Is T the same as tanker?
No. Tanker is the N endorsement. The letters confuse people because the tanker endorsement is sometimes called "tank" and T is doubles/triples.
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