Vehicle Inspection — CDL General Knowledge Practice Test

This CDL General Knowledge Vehicle Inspection practice set has 54 practice questions based on the official exam materials, each with an instant explanation. You need 80% on the real CDL General Knowledge knowledge test to pass.

Sample questions

Three questions from the Vehicle Inspection bank with the correct answer and an explanation. The practice quiz above draws 30 questions at random from the same bank.

1. What is the most important reason to inspect your vehicle?

   • Safety — for yourself and for other road users — Correct answer
   • To improve fuel economy
   • To avoid paying tolls
   • Only because a logbook requires it

   Explanation: Safety is the #1 reason to inspect — for yourself and for other road users; a defect found before driving can prevent crashes. English term: pre-trip inspection（出车前检查 / inspección antes del viaje）.

   Handbook: Vehicle Inspection — Why Inspect

2. If you find something unsafe during your inspection, what does the law say about driving the vehicle?

   • Federal and state laws forbid operating an unsafe vehicle — Correct answer
   • You may drive it as long as you report the defect later
   • You may drive it if the trip is under 50 miles
   • It is allowed at the driver's own discretion

   Explanation: Federal and state laws forbid operating an unsafe vehicle — if you find anything unsafe, get it fixed before driving. English term: out-of-service order（停驶令 / orden de fuera de servicio）.

   Handbook: Vehicle Inspection — Why Inspect

3. What is the minimum tread depth required in every major groove of the front (steering) tires?

   • 4/32 inch — Correct answer
   • 2/32 inch
   • 1/32 inch
   • 6/32 inch

   Explanation: Front/steer tires need at least 4/32 inch of tread in every major groove; other tires need 2/32 inch. English term: tread depth（胎纹深度 / profundidad de la banda de rodadura）.

   Handbook: Vehicle Inspection — Tires