California CDL General Knowledge Practice Test

The California CDL General Knowledge test has 50 questions. You must answer at least 40 correctly — a passing score of 80% — to pass.

California issues three CDL classes: Class A (combination vehicles with a GVWR over 26,001 lbs and a towed unit over 10,000 lbs), Class B (single vehicles over 26,001 lbs, or towing a trailer under 10,001 lbs), and Class C (vehicles designed to transport 16 or more passengers including the driver, or carrying hazardous materials requiring placards).

Yes. After passing the General Knowledge test, you must also pass endorsement-specific knowledge tests for any special vehicle types you want to operate: Passenger (P), School Bus (S), Tank Vehicles (N), Hazardous Materials (H), Doubles and Triples (T), or Air Brakes (restriction removed). You must also pass a CDL skills test (pre-trip inspection, basic vehicle control, and road test) in the vehicle class you are applying for.

Yes. A CDL issued by California is valid in all 50 states for the vehicle class and endorsements listed on the license. However, you must always comply with the laws of the state in which you are driving.

A California CDL is valid for 5 years. If you hold a HazMat endorsement, it requires a TSA security threat assessment (background check) renewal every 5 years as well. Your medical certificate (DOT physical) must be kept current throughout your CDL validity.

A Class A CDL allows you to operate any combination of vehicles with a Gross Vehicle Weight Rating (GVWR) of 26,001 lbs or more, provided the towed unit exceeds 10,000 lbs — this includes tractor-trailers and double/triple trailer rigs. A Class B CDL covers single vehicles with a GVWR of 26,001 lbs or more, or any such vehicle towing a unit not exceeding 10,000 lbs — this includes straight trucks and large buses. A Class C CDL is required for vehicles designed to carry 16 or more passengers (including the driver) or for vehicles transporting hazardous materials that require placarding, when those vehicles do not qualify for Class A or B.

CDL fees vary by state and by the class and endorsements you obtain. Most states charge separate fees for the CDL knowledge test ($10–$30 per attempt), the CDL skills test ($50–$150), and the CDL license itself ($50–$100). Additional fees apply for each endorsement (HazMat, Tanker, Passenger, etc.). The HazMat endorsement also requires a TSA security threat assessment fee of approximately $86. Check your California DMV website for current fee schedules.

Federal regulations (49 CFR 383.133) require that CDL applicants be able to read and speak the English language sufficiently to understand highway traffic signs and signals and to respond to official inquiries. Many states offer CDL knowledge tests in Spanish and other languages for non-commercial knowledge questions, but the actual CDL test must be taken in a language that allows the driver to meet the English proficiency requirement. Check with the California DMV for available language options.

In most states, a CDL is valid for 4–8 years (commonly 4–5 years). To renew your California CDL, you typically need to visit a DMV office, pass a vision test, pay the renewal fee, and update your medical certification (DOT physical). If you hold a HazMat endorsement, your TSA background check must also be current. CDLs cannot generally be renewed online due to federal requirements for in-person verification of medical certification.

If you fail the CDL General Knowledge test in California, you are typically required to wait a specified period (commonly 1–7 days) before retaking it. Most states allow 2–3 attempts before requiring additional waiting periods or study requirements. There is usually a retest fee for each attempt. Focus on the areas you missed — most states provide a score sheet showing which topic areas you need to review.