Code T
Compatible with: Class A
Doubles & Triples Endorsement
Pull more trailers. Earn more per mile.
Difficulty
Moderate
Salary Impact
5–15% above single-trailer positions
TSA Required
No
What Is the Doubles/Triples Endorsement?
The Doubles/Triples endorsement (code T) authorizes CDL holders to pull two or three trailers simultaneously. It is required for LTL (less-than-truckload) carriers that operate double-trailer configurations and is common in parcel and freight networks. The endorsement adds significant value to a Class A CDL.
Who Needs This Endorsement?
Class A CDL holders who want to operate double or triple trailer combinations. Required by LTL carriers including FedEx Freight, UPS Freight, Old Dominion, and ABF Freight for certain positions.
How to Obtain It
- 1Pass the Doubles/Triples knowledge test at DPS (20 questions; 80% passing score)
- 2Must hold a valid Class A CDL
- 3No additional background check required
- 4Renewal with CDL renewal
Knowledge Test Topics
Study Tips
- Master the coupling and uncoupling sequence for converter dollies
- Understand how rearward amplification affects multi-trailer combinations
- Study the inspection checklist for converter dollies
- Review state-by-state triple trailer permit requirements
- Practice braking distance calculations for heavier combinations
Career Impact
Opens LTL carrier positions that often offer consistent regional miles, home-weekly or home-nightly schedules, and above-average pay. FedEx Freight, UPS Freight, and Old Dominion actively recruit doubles-endorsed drivers.
How Diesel Xtrem Prepares You
We cover the Doubles/Triples knowledge test material and help you understand the coupling and stability concepts that DPS examiners test. Add this endorsement efficiently alongside your Class A CDL.