Licenses & Endorsements
Doubles/Triples Endorsement (T Endorsement)
The Doubles/Triples (T) endorsement authorizes a CDL holder to operate combination vehicles pulling two or three trailers at once. It requires a written knowledge test covering the handling characteristics unique to multi-trailer combinations, such as increased stopping distance and the risk of trailer sway or “crack the whip” effects.
Multi-trailer combinations behave differently from a standard single tractor-trailer: they require longer stopping distances, are more susceptible to trailer sway at speed, and demand more careful handling in coupling, backing, and turning. The T endorsement's knowledge test covers these risks specifically. Doubles and triples configurations are most common in LTL (less-than-truckload) line-haul operations and certain regional lanes where carriers run multiple trailers between terminals, rather than in typical long-haul truckload freight.
Why it matters for recruiting and operations
Doubles/triples freight represents a smaller, more specialized segment of trucking recruiting, concentrated among LTL and line-haul carriers rather than general truckload fleets. Carriers hiring for these roles typically prioritize experience with multi-trailer handling in addition to the endorsement itself, since the written test alone doesn't guarantee comfort backing or coupling multiple trailers.
Related terms
Where this shows up in Fleegital
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