Core CDL Test

CDL General Knowledge Practice Tests

The General Knowledge test is the one exam every CDL applicant has to pass — Class A, B, or C, every endorsement, no exceptions. Practice free for your state below.

About the General Knowledge Test

The General Knowledge test is the foundation of the entire CDL. Before you can add a single endorsement or sit for a skills test, you have to pass it. It pulls directly from your state's CDL handbook and covers the fundamentals of operating any commercial vehicle safely on public roads.

Expect questions on vehicle inspection basics, controlling your speed and space, seeing hazards early, communicating with signals and lights, distracted and aggressive driving, and what to do at the scene of an accident. The exact question count and passing score vary by state, but the core material is federal and consistent everywhere.

From Pedro, behind the wheelWhen I tested in Arizona, General Knowledge was the section that actually decided whether I'd be driving for a living. People treat it like the easy one and walk in cold — then get buried by the space-management and hazard-perception questions. Read the handbook section on managing space twice. That's where the points hide.

What Test-Takers Miss Most

  • 1Managing space and following distance — The handbook's one-second-per-10-feet rule and the adjustments for speed and weather come up constantly, and the wording trips people up.
  • 2Controlling speed on downgrades — Questions on engine braking, selecting a low gear before the hill, and why you don't ride the brakes catch a lot of first-timers.
  • 3Seeing hazards early — Hazard perception isn't memorization — it's reasoning about what a situation could turn into. Slow down and picture each scenario.

Choose Your State

Each state's test reflects its own CDL handbook, question count, and passing score. Pick yours to start a free General Knowledge practice test built for 2026.

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