Commercial driver license (CDL) knowledge tests

What to expect on the test

A Texas commercial driver license takes several knowledge exams, given in a fixed order: Texas Commercial Rules first, then General Knowledge, and then each endorsement you need, such as combination vehicles, air brakes, doubles and triples, passenger, school bus, tank and hazardous materials. The Texas Commercial Motor Vehicle Drivers Handbook asks for 80 percent on each one. After a failed exam the application stays open for 90 days, and three failed attempts void it.

The questions here are written from that handbook, March 2026 edition, for every exam on the list, including section 14 on the special requirements for Texas commercial vehicles: papers and permits, equipment, and the size and weight limits. Every answer links to its page in the handbook. Each exam has its own practice test, so you can prepare for exactly the endorsements you need.

Start with Texas Commercial Rules and General Knowledge, which everyone takes, then add the endorsements. The hazardous materials endorsement also needs a background check: the practice here covers the knowledge part.

Frequently asked questions