California General Knowledge CDL Practice Test
Below are 25 exam-style questions for the California General Knowledge CDL knowledge test, modeled on the FMCSA-aligned content used by the California Department of Motor Vehicles. Try to answer each question on your own before reading the answer key directly under it. The questions and answer choices are shuffled deterministically per state and endorsement, so the order will stay the same on repeat visits — that lets you genuinely measure your improvement.
- A Gross Vehicle Weight Rating
- B General Vehicle Weight Reading
- C Gross Vehicle Width Rating
- D Government Vehicle Weight Regulation
- A Signal only at the moment you start turning
- B Signal only when other vehicles are present
- C Use the four-way flashers instead of signals at intersections
- D Signal early, signal continuously, and cancel after the turn
- A 11 hours
- B 16 hours
- C 14 hours
- D 10 hours
- A Coast in neutral
- B Stay in high gear
- C Select a lower gear before starting down
- D Use the parking brake intermittently
- A A fuel-saving switch
- B A low-air pressure warning device that drops a flag in front of the driver
- C A trailer hitch component
- D A type of cargo strap
- A Make eye contact only when stopped
- B Tap the horn lightly or flash lights to signal your presence
- C Honk loudly to warn other drivers
- D Never communicate; just drive
- A 26,001 lbs or more
- B 40,000 lbs or more
- C 20,000 lbs or more
- D 10,001 lbs or more
- A High beams improve visibility in heavy rain
- B It is safe to drive at the posted speed limit
- C Roads are most slippery just after rain begins, when water mixes with road oil
- D Tire chains are required by federal law
- A Tires lose contact with the road on a film of water
- B Roads are dry but hot
- C Tires are over-inflated
- D You brake hard on dry pavement
- A A spotter walking 1,000 ft up the road
- B Three reflective triangles: 10 ft, 100 ft, and 200 ft toward approaching traffic
- C A flare burning constantly
- D One reflective triangle within 10 feet
- A Use a low gear and steady moderate brake application
- B Disengage the clutch and coast
- C Use the parking brake to slow down
- D Pump the brakes hard and fast
- A All of the above
- B Frequent yawning
- C Trouble remembering the last few miles
- D Drifting in your lane
- A Driving over a speed bump
- B Setting the parking brake, releasing the service brakes, and gently trying to move the vehicle in low gear
- C Pumping the brakes
- D Releasing the parking brake on a flat surface and tugging gently against it
- A Allowed off-duty only
- B A traffic violation, but not a CDL disqualification
- C Considered driving under the influence for CDL purposes
- D Allowed if the driver feels fine
- A Engine oil level is safe to operate
- B Coolant level is above LOW and the cap is secure
- C Power steering fluid is at the proper level
- D All of the above
- A Doubles
- B Stays the same
- C Quadruples
- D Triples
- A 7 days
- B A reasonable time, before going off duty
- C 1 hour
- D 24 hours
- A Move to the left lane only
- B Speed up to get away
- C Increase your following distance from the vehicle in front to give both of you more room
- D Brake suddenly to teach a lesson
- A Class A combinations only
- B Vehicles designed to carry 16+ passengers including the driver, or that require hazmat placards
- C Any vehicle over 26,001 lbs
- D Tractor-trailers under 26,001 lbs GCWR
- A To rest the right leg
- B So the brake lights don't mislead following drivers and so the brakes don't overheat
- C To save brake pads and reduce drag
- D To save fuel and improve mileage
- A Only at night
- B Only on the highway
- C When you are stopped or moving slowly enough to be a hazard
- D Whenever you feel like it
- A All of the above
- B Brakes alone are not designed to hold a heavy vehicle on a long downgrade
- C Engine braking helps keep speed under control
- D Heavy vehicles can slow down sharply on grades
- A The full range of high-beam headlights when in use
- B Half the range of your low-beam headlights
- C Whatever speed feels safe
- D The range of your low-beam headlights
- A Took the test and passed
- B Need to take it again later
- C Took the test and failed
- D Did not take the test, with no consequence
- A Shift to neutral and coast
- B Steer sharply toward the shoulder
- C Hold the steering wheel firmly, ease off the accelerator, and let the vehicle slow down
- D Brake immediately and pull off the road
Study tips for the California General Knowledge exam
The General Knowledge portion of the California CDL exam is graded out of the bank of questions the California Department of Motor Vehicles draws from each year. While the exact bank is not published, every question is sourced from the General Knowledge chapter of the California CDL handbook, which itself is derived from the FMCSA Model Commercial Driver's License Manual. That means studying our practice tests, reading the corresponding handbook chapter, and re-reading the parts you got wrong is genuinely the most efficient route to a first-time pass.
Most successful applicants follow a simple cycle: take the practice test cold, write down every question you missed, open the matching chapter of the official California handbook, re-read the section that contains the right answer, then re-take the practice test 24 to 48 hours later. The 24-hour delay matters — sleep is when your brain commits new information to long-term memory, and CDL knowledge questions reward that kind of consolidated learning rather than cramming.
Pay particular attention to questions that include qualifier words like always, never, only, primary, or most. CDL test writers love to flip the right answer with a single qualifier. When two answer choices look almost identical, pay attention to the verb (is it must, should, or may?) and to any numbers (14 days, 100 air miles, 8 hours, 70/8 split). On endorsement tests in particular, watch for trick framing where a true statement about a different endorsement is offered as the "correct" answer to a question that is actually about General Knowledge.
Test-day logistics matter too. Bring photo ID, your Social Security card or birth certificate, your medical examiner's certificate (DOT card), and proof of state residency if you haven't already submitted those documents. The California Department of Motor Vehicles will not let you sit for the knowledge exam without your documentation, and most offices charge an additional fee for re-attempts. Arrive early — the wait at most CDL testing offices runs 30 to 60 minutes — and silence your phone before the exam begins.
Finally, keep your General Knowledge fundamentals sharp even when you're focused on the General Knowledge exam. Many states administer multiple knowledge tests in a single sitting, and questions on weight definitions (GVWR, GCWR, GAWR), stopping distance, and the pre-trip inspection routine show up across endorsements. If you're unsure on the basics, sit a fresh California General Knowledge practice test before scheduling the real exam.
Next steps
Missed more than four questions? Re-read the General Knowledge study guide and the matching chapter in the official California CDL handbook. Then come back and re-take the test. Once you can score 22 of 25 or higher on three runs in a row, you're in good shape to schedule the real exam at your local California Department of Motor Vehicles office.
Already comfortable with this endorsement? Drill another: CA Air Brakes · CA Combination Vehicles · CA Hazardous Materials · CA Passenger · CA School Bus · CA Tank Vehicle · CA Doubles / Triples
New to the CDL process in California? Read How to apply for a CDL in California for the document checklist and step-by-step timeline.