California CDL knowledge practice
Review commercial-driver knowledge topics with original handbook-based questions. This is study help, not the DMV.
General Knowledge · Air Brakes · Combination Vehicles
Last reviewed: August 31, 2026
Start with 10 randomized questions, review each explanation, and continue when ready.
Independent educational practice only. Only the California DMV issues a CDL. Confirm current requirements in the California Commercial Driver Handbook.
Best free study order
- Read California CDL handbook sections for General Knowledge, Air Brakes, and Combination Vehicles.
- Take the subject tests here until you consistently score 90% or higher.
- Write down every missed topic, not just the missed question.
- Drill the 50-question mock and the flashcards before permit day.
Official sources: California Commercial Driver Handbook and DMV Sample Commercial Test 1. Last reviewed August 31, 2026. See an error? Tell us.
Common questions
Are these official DMV questions?
No. Original handbook-style practice. Only the California DMV issues a CDL.
What should I study first?
Start with General Knowledge, then Air Brakes and Combination Vehicles.