California Doubles/Triples Endorsement Test

California's doubles/triples (T) endorsement is knowledge-only — there's no separate skills test — and costs $59 to add to a Class A or B CDL. (source)

One California-specific wrinkle worth knowing before you study: triple trailers themselves are not legal to operate in California, even though the state still tests and issues the T endorsement. (source)

California groups the doubles/triples endorsement with tank (N) and hazmat (X) at the same $59 price point on a Class A or B CDL — a different bracket than the $100 California charges to add a passenger endorsement to the same class of license. (source)

Like every California CDL knowledge test, you get three attempts at the T written exam on one application — fail it a third time and California voids the application, so you'd reapply and pay again. (source)

The doubles/triples test itself focuses on coupling and uncoupling procedures, how to inspect the connections between units, and how pulling multiple trailers changes braking distance and off-tracking through a turn — all covered in the state's own commercial driver handbook rather than in a separate published question bank. (source)