Missouri CDL General Knowledge Practice Test

The Missouri CDL General Knowledge test is a multiple-choice knowledge test you take for your commercial learner's permit. Missouri Department of Revenue (licenses) and Missouri State Highway Patrol (testing) says you need 80% to pass (source).

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 Missouri 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.

Missouri CDL permit facts

What	What Missouri says	Source
General Knowledge pass mark	80%	Official page
General Knowledge test questions	50	Official page
CLP fee	$44, which is a $25 written test fee, a $10 permit fee and a $9 office fee. Pay by card, check or cash	Official page
Duplicate CLP fee	$14	Official page
CLP validity	360 days. It cannot be renewed. When it ends you must pass all the knowledge tests again for a new CLP	Official page
CLP holding period	Hold the CLP at least 14 days before the CDL skills test. The test paper alone is not a permit	Official page
Knowledge test retest rule	You may retake a failed test right away, but the examiner can make you come back on a later day	Official page
Test languages	Commercial knowledge tests are English only, and no translators are allowed (RSMo 302.720).	Official page

20 question General Knowledge practice test

1. How do you test the parking brake during an inspection?
1. A. Set it on a hill and wait to see if the vehicle rolls
2. B. Drive at 20 mph and apply only the parking brake
3. C. Put the transmission in neutral and check how far the lever moves
4. D. Set it, put the vehicle in a low gear, and gently pull forward against it
Show answer
Answer: D. Set it, put the vehicle in a low gear, and gently pull forward against it
The manual's test is to place the vehicle in a low gear and gently pull forward against the set parking brake.
From the official CDL manual, section 2.1.5.
2. While driving with a covered load, how should you check the cover?
1. A. Never look at it until you stop
2. B. Check it only at night
3. C. Ask other drivers to check it
4. D. Look at it in your mirrors from time to time
Show answer
Answer: D. Look at it in your mirrors from time to time
The manual says to look at your cargo covers in the mirrors from time to time while driving.
From the official CDL manual, section 3.3.4.
3. At 55 mph, how far do you travel while looking away for the average text, 4.6 seconds?
1. A. 142 feet
2. B. 216 feet
3. C. 306 feet
4. D. 371 feet
Show answer
Answer: D. 371 feet
At 55 mph, 4.6 seconds off the road means traveling 371 feet.
From the official CDL manual, section 2.9.5.
4. Why do empty trucks need greater stopping distances than loaded trucks?
1. A. Their brakes work best when empty
2. B. Their brakes absorb more heat when empty
3. C. They are lighter, so they roll farther
4. D. An empty vehicle has less traction
Show answer
Answer: D. An empty vehicle has less traction
The manual says an empty vehicle has less traction, so it needs more distance to stop.
From the official CDL manual, section 2.6.1.
5. A shipping container is loaded onto a flatbed trailer. How must it be secured?
1. A. It needs no tie-downs because it is sealed
2. B. It needs no tie-downs because it is heavy
3. C. Properly secured, just like any other cargo
4. D. Only the door lock needs to be checked
Show answer
Answer: C. Properly secured, just like any other cargo
Containers must be properly secured just like any other cargo.
From the official CDL manual, section 3.3.5.
6. If a distracted driver reacts a half-second slower, what happens to crashes?
1. A. Crashes increase by about 10 percent
2. B. Crashes triple
3. C. Crashes double
4. D. Crashes stay about the same
Show answer
Answer: C. Crashes double
The manual says that a half-second slower reaction because of distractions doubles crashes.
From the official CDL manual, section 2.9.6.
7. You see rust streaks around the wheel nuts. What might this mean?
1. A. Nothing, because rust is normal on wheels
2. B. The tire is overinflated
3. C. The brake drum is cracked
4. D. The nuts may be loose, so you should check their tightness
Show answer
Answer: D. The nuts may be loose, so you should check their tightness
The manual says rust around wheel nuts may mean the nuts are loose.
From the official CDL manual, section 2.1.3.
8. 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.
9. How do you warn drivers behind you before a tight turn in a large vehicle?
1. A. Brake late and hard at the turn
2. B. Speed up first, then slow quickly
3. C. Flash your high beams
4. D. Brake early and slow down gradually
Show answer
Answer: D. Brake early and slow down gradually
Braking early and slowing gradually gives following drivers warning.
From the official CDL manual, section 2.5.1.
10. How should you use caffeine when you are tired?
1. A. It cures fatigue if you drink enough
2. B. It can replace rest on a long run
3. C. It helps for a few hours but wears off, so do not rely on it
4. D. It works better than a short nap
Show answer
Answer: C. It helps for a few hours but wears off, so do not rely on it
Caffeine only boosts awareness for a while, so do not count on it to prevent fatigue.
From the official CDL manual, section 2.11.2.
11. What can a broken coolant hose lead to while you drive?
1. A. Better fuel economy
2. B. Longer tire life
3. C. Engine failure and even fire
Show answer
Answer: C. Engine failure and even fire
A broken hose can lead to engine failure and even fire.
From the official CDL manual, section 2.14.1.
12. At what blood alcohol concentration (BAC) is it illegal to operate a CMV?
1. A. .04% or more
2. B. .02% or more
3. C. .06% or more
4. D. .08% or more
Show answer
Answer: A. .04% or more
It is illegal to operate a CMV at a BAC of .04% or more.
From the official CDL manual, section 1.3.
13. 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.
14. Which hazard class includes uranium and plutonium?
1. A. Class 5, Oxidizers
2. B. Class 6, Poisons
3. C. Class 7, Radioactive
4. D. Class 3, Flammable
Show answer
Answer: C. Class 7, Radioactive
The hazard class table lists uranium and plutonium as Class 7, Radioactive.
From the official CDL manual, section 2.23.3.
15. Why remove ice and snow from hand holds, steps, and deck plates?
1. A. To lower the weight of the truck
2. B. To help the engine start
3. C. To reduce the danger of slipping
Show answer
Answer: C. To reduce the danger of slipping
Clearing them reduces the danger of slipping.
From the official CDL manual, section 2.13.1.
16. Which hazard class includes hydrochloric acid and battery fluid?
1. A. Class 3, Flammable
2. B. Class 5, Oxidizers
3. C. Class 6, Poisons
4. D. Class 8, Corrosives
Show answer
Answer: D. Class 8, Corrosives
Hydrochloric acid and battery fluid are examples of Class 8 corrosives.
From the official CDL manual, section 2.23.3.
17. What does a front-end header board (headache rack) do?
1. A. Keeps rain off the cargo
2. B. Protects you from your cargo in a crash or emergency stop
3. C. Keeps the load from sliding out the back
4. D. Holds the cover tight
Show answer
Answer: B. Protects you from your cargo in a crash or emergency stop
A header board shields the driver from the cargo during a crash or emergency stop.
From the official CDL manual, section 3.3.3.
18. Where is the yellow ABS malfunction lamp on a trailer?
1. A. On the right side, at the front corner
2. B. Inside the cab on the dash
3. C. On the left side, at the front or rear corner
4. D. Under the trailer floor
Show answer
Answer: C. On the left side, at the front or rear corner
Trailers have the yellow lamp on the left side, on the front or rear corner.
From the official CDL manual, section 2.18.3.
19. What should you check about the splash guards at the rear?
1. A. They are painted
2. B. They are present, fastened, and not rubbing the tires
3. C. They are removed
4. D. They touch the ground
Show answer
Answer: B. They are present, fastened, and not rubbing the tires
Splash guards should be present, not damaged, properly fastened, and not dragging or rubbing tires.
From the official CDL manual, section 2.1.5.
20. Traffic is stopped just past a railroad crossing. What should you do?
1. A. Wait until you can get all the way across the tracks
2. B. Pull onto the tracks and wait
3. C. Stop with your rear wheels on the tracks
4. D. Cross and stop right after the tracks
Show answer
Answer: A. Wait until you can get all the way across the tracks
Be sure you can get all the way across before you start across.
From the official CDL manual, section 2.15.5.

Missouri CDL General Knowledge questions

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

Missouri says you need 80% to pass the General Knowledge test.

Is the Missouri 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. Missouri uses its own handbook: https://dor.mo.gov/forms/Commerical_Driver_License.pdf

How much does a CDL permit cost in Missouri?

CLP fee: $44, which is a $25 written test fee, a $10 permit fee and a $9 office fee. Pay by card, check or cash.

What languages is the Missouri CDL knowledge test offered in?

Commercial knowledge tests are English only, and no translators are allowed (RSMo 302.720).

Sources

https://dor.mo.gov/resources/official-final-rules/documents/12_CSR_10-24_300_CDL_Written_Examinations_Final.pdf
https://dor.mo.gov/driver-license/issuance/commercial/
https://dor.mo.gov/driver-license/documents/feechart.pdf
https://dor.mo.gov/driver-license/issuance/commercial/cdl-permit.html
https://dor.mo.gov/faq/driver-license/cdl-clp.html
https://dor.mo.gov/forms/Commerical_Driver_License.pdf
Manual sections used in this test: 1.3; 2.1.3; 2.1.5; 2.11.2; 2.13.1; 2.14.1; 2.15.5; 2.18.3; 2.23.3; 2.3.1; 2.5.1; 2.6.1; 2.7.2; 2.9.5; 2.9.6; 3.3.3; 3.3.4; 3.3.5

General Knowledge practice test in nearby states