California CDL General Knowledge Practice Test

The California CDL General Knowledge test is a multiple-choice knowledge test you take for your commercial learner's permit. You need at least 80% to pass. That's the federal minimum in 49 CFR 383.135 (California does not publish its own number).

Last updated Oct 7, 2026. FirstTry CDL is a CDL permit test prep site by Hive Asset Group, LLC.

By Scott Wilder, Editor

Last reviewed against the California CDL manual on October 7, 2026

Scott Wilder on X | scottwilderhq.com

FirstTry CDL is a CDL permit test prep site by Hive Asset Group, LLC. It offers free exam-style practice tests built from the official CDL manual. FirstTry CDL is not affiliated with any DMV, FMCSA or government agency. Practice questions are exam-style questions built from the official CDL manual, not actual test questions.

California CDL permit facts

What	What California says	Source
General Knowledge pass mark	At least 80%. This is the federal minimum (49 CFR 383.135); California does not publish its own number.	Official page
CLP fee	No separate CLP fee is listed. You pay the nonrefundable application fee ($100 for Class A or B, $59 for Class C commercial) when you apply, good for 12 months	Official page
CLP validity	Up to 180 days from issue. It can be renewed for another 180 days if the expiration is not more than one year from the first application date	Official page
CLP holding period	Hold the CLP at least 14 days before the skills test	Official page
Test languages	The DMV commercial handbook (2019 edition) says commercial knowledge tests are offered in English, Arabic, Chinese, Punjabi, Russian and Spanish. Skills tests must be done in English and interpreters are not allowed. No English-only rule for commercial knowledge tests was found on dmv.ca.gov as of October 2026.	Official page

20 question General Knowledge practice test

1. An oncoming driver keeps high beams on. What should you do?
1. A. Turn on your high beams too
2. B. Do not put on your own high beams to get back at the driver
3. C. Flash your high beams until the driver dims
4. D. Stare at the oncoming lights
Show answer
Answer: B. Do not put on your own high beams to get back at the driver
Using your own high beams increases glare and the chance of a crash.
From the official CDL manual, section 2.11.5.
2. You report an aggressive driver to the police. Which detail should you give?
1. A. The driver's name and age
2. B. The driver's job
3. C. The vehicle description and license number
4. D. The driver's home address
Show answer
Answer: C. The vehicle description and license number
The manual says to give a vehicle description, license number, location, and direction of travel if possible.
From the official CDL manual, section 2.10.3.
3. Why should you change lanes slowly and smoothly?
1. A. It keeps the mirrors clean.
2. B. It saves fuel.
3. C. It lets you skip the turn signal.
4. D. A driver you did not see may have time to honk or avoid you.
Show answer
Answer: D. A driver you did not see may have time to honk or avoid you.
A slow, smooth change gives a driver you did not see a chance to react.
From the official CDL manual, section 2.5.1.
4. You drive a 40-foot vehicle below 40 mph. How many seconds should you leave between you and the vehicle ahead?
1. A. 3 seconds
2. B. 4 seconds
3. C. 6 seconds
4. D. 8 seconds
Show answer
Answer: B. 4 seconds
The rule is one second for each 10 feet of vehicle length, so 40 feet means 4 seconds.
From the official CDL manual, section 2.7.1.
5. What do accident statistics show about drivers who have been drinking?
1. A. Their crash risk is the same as other drivers
2. B. Only new drivers crash more
3. C. Their crash risk is a little lower
4. D. Their crash risk is much greater
Show answer
Answer: D. Their crash risk is much greater
Accident statistics show the chance of a crash is much greater for drivers who have been drinking.
From the official CDL manual, section 2.22.1.
6. Your mirrors and wiper blades have ice on them. What does this tell you?
1. A. Tire pressure is low
2. B. The road is dry
3. C. The heater is working well
4. D. The road is most likely icy too
Show answer
Answer: D. The road is most likely icy too
Ice on mirrors and wipers means the road most likely is icy as well.
From the official CDL manual, section 2.13.2.
7. Why should you downshift to the right gear before entering a curve?
1. A. So you can brake harder in the curve
2. B. So the engine can coast and rest in the curve
3. C. So you can shift gears in the middle of the curve
4. D. So you can use some power through the curve, which helps stability
Show answer
Answer: D. So you can use some power through the curve, which helps stability
Downshifting first lets you keep some power on in the curve, which helps the vehicle stay stable.
From the official CDL manual, section 2.3.1.
8. With no stop line, how far from the nearest rail must a required stop be made?
1. A. No closer than 5 feet and no farther than 15 feet
2. B. No closer than 50 feet and no farther than 100 feet
3. C. No closer than 15 feet and no farther than 50 feet
4. D. Right at the rail, within 5 feet
Show answer
Answer: C. No closer than 15 feet and no farther than 50 feet
Stop between 15 and 50 feet from the nearest rail.
From the official CDL manual, section 2.15.2.
9. How does alcohol get to your brain?
1. A. It is first processed by the liver
2. B. It must pass through the lungs first
3. C. It is first removed in urine
4. D. It goes directly into the blood stream
Show answer
Answer: D. It goes directly into the blood stream
Alcohol goes directly into the blood stream and is carried to the brain.
From the official CDL manual, section 2.22.1.
10. A modern truck climbs a hill in a high gear. Which gear may it need going down?
1. A. Always the same gear used to climb
2. B. A lower gear than it used to climb
3. C. Always a higher gear than it used to climb
4. D. Neutral
Show answer
Answer: B. A lower gear than it used to climb
Modern trucks have less friction and drag, so they may need lower gears going down.
From the official CDL manual, section 2.16.2.
11. What can a flapping cargo cover do?
1. A. Tear loose, uncover the cargo, and block someone's view
2. B. Make the cargo lighter
3. C. Lower the vehicle's center of gravity
4. D. Make a little noise but cause no safety problem
Show answer
Answer: A. Tear loose, uncover the cargo, and block someone's view
A flapping cover can tear loose and block your view or someone else's.
From the official CDL manual, section 3.3.4.
12. You must leave the road in an emergency. What helps you keep control?
1. A. Put all wheels on the soft shoulder
2. B. Turn sharply toward the ditch
3. C. Brake hard as soon as you leave the road
4. D. Keep one set of wheels on the pavement if possible
Show answer
Answer: D. Keep one set of wheels on the pavement if possible
Keeping one set of wheels on the pavement helps you maintain control.
From the official CDL manual, section 2.17.1.
13. Your tire pressure reads high after hours in the heat. What should you do?
1. A. Leave the air in, because pressure rises with heat
2. B. Let air out until the gauge shows the cold pressure
3. C. Pour cold water on the tires right away
4. D. Drive faster to cool the tires with airflow
Show answer
Answer: A. Leave the air in, because pressure rises with heat
Heat raises tire pressure, so do not release air or the tires will be underinflated when cool.
From the official CDL manual, section 2.14.1.
14. What is the most a driver can be fined in civil penalties for violating the texting prohibition?
1. A. $500
2. B. $1,000
3. C. $2,750
4. D. $11,000
Show answer
Answer: C. $2,750
Drivers face civil penalties of up to $2,750 for each violation.
From the official CDL manual, section 2.9.5.
15. Your personal vehicle license is suspended for an alcohol violation. What happens to your CDL?
1. A. You lose your CDL for 1 year
2. B. Nothing, since it was not a CMV
3. C. You can keep driving a CMV if you do not carry hazmat
4. D. You lose your CDL for only 24 hours
Show answer
Answer: A. You lose your CDL for 1 year
An alcohol suspension in a personal vehicle costs you your CDL for 1 year.
From the official CDL manual, section 1.3.
16. Before you start down a long, steep hill, what gear should you be in?
1. A. A higher gear than you used to climb, to save fuel
2. B. Neutral, so the vehicle coasts and the brakes stay cool
3. C. A low gear, usually lower than the one needed to climb the hill
4. D. Any gear, because the brakes will control your speed
Show answer
Answer: C. A low gear, usually lower than the one needed to climb the hill
The manual says to downshift before the hill, usually to a gear lower than the climbing gear.
From the official CDL manual, section 2.3.1.
17. When may you fully apply the brakes in an emergency stop with ABS?
1. A. Whenever ABS is on only the tractor
2. B. Whenever the road is dry
3. C. Whenever ABS is on only the trailer
4. D. With a straight truck or combination that has working ABS on all axles
Show answer
Answer: D. With a straight truck or combination that has working ABS on all axles
Working ABS on all axles is the one exception to braking only as hard as needed.
From the official CDL manual, section 2.18.6.
18. A car is following you too closely. What is a good response?
1. A. Speed up to get away from it
2. B. Brake hard to make it back off
3. C. Flash your brake lights over and over
4. D. Increase your following distance
Show answer
Answer: D. Increase your following distance
More room in front helps you avoid sudden speed or direction changes.
From the official CDL manual, section 2.7.2.
19. How should you set the lights inside your cab at night?
1. A. Interior light on and gauges bright
2. B. All lights as bright as possible
3. C. Interior light off and gauges as low as you can still read
4. D. Interior light dim and gauges off
Show answer
Answer: C. Interior light off and gauges as low as you can still read
A bright cab makes it harder to see outside, so keep the interior light off and gauges low.
From the official CDL manual, section 2.11.5.
20. When you shift down, you shift to neutral and release the clutch. What do you do next?
1. A. Press the accelerator to raise engine speed to the rpm for the lower gear
2. B. Let the engine slow down to the rpm of the lower gear
3. C. Push the brake pedal hard
4. D. Turn the engine off
Show answer
Answer: A. Press the accelerator to raise engine speed to the rpm for the lower gear
The manual says to increase engine and gear speed to the rpm needed in the lower gear.
From the official CDL manual, section 2.3.1.

California CDL General Knowledge questions

What score do you need to pass the California CDL General Knowledge test?

You need at least 80% to pass. That is the federal minimum in 49 CFR 383.135. California does not publish its own number.

Is the California CDL General Knowledge test the same as other states?

The General Knowledge test is built on the same federal knowledge standards in every state, so the topics match the CDL manual. California uses its own handbook: https://www.dmv.ca.gov/web/eng_pdf/comlhdbk.pdf

How much does a CDL permit cost in California?

CLP fee: No separate CLP fee is listed. You pay the nonrefundable application fee ($100 for Class A or B, $59 for Class C commercial) when you apply, good for 12 months.

What languages is the California CDL knowledge test offered in?

The DMV commercial handbook (2019 edition) says commercial knowledge tests are offered in English, Arabic, Chinese, Punjabi, Russian and Spanish. Skills tests must be done in English and interpreters are not allowed. No English-only rule for commercial knowledge tests was found on dmv.ca.gov as of October 2026.

Sources

https://www.ecfr.gov/current/title-49/section-383.135
https://www.dmv.ca.gov/portal/driver-licenses-identification-cards/licensing-fees/
https://www.dmv.ca.gov/portal/driver-licenses-identification-cards/commercial-driver-licenses-cdl/
https://www.dmv.ca.gov/web/eng_pdf/comlhdbk.pdf
Manual sections used in this test: 1.3; 2.10.3; 2.11.5; 2.13.2; 2.14.1; 2.15.2; 2.16.2; 2.17.1; 2.18.6; 2.22.1; 2.3.1; 2.5.1; 2.7.1; 2.7.2; 2.9.5; 3.3.4

General Knowledge practice test in nearby states