Colorado General Knowledge CDL Practice Test
25 realistic General Knowledge practice questions for Colorado CDL applicants. Required for: All CDL applicants (Class A, B, and C). Official test: 50 questions, 40 correct to pass.
Question 1 of 25 · Emergency Equipment
Most heavy vehicle fires are caused by:
-
A.
Hot tires from low pressure or under-inflated duals
-
B.
Cold weather
-
C.
Engine cooling system
-
D.
Exhaust pipes only
Correct answer: A.
Hot tires and brakes are leading causes. Inspect tires and brakes regularly to prevent fires.
Question 2 of 25 · ABS
ABS:
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A.
Allows you to drive faster
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B.
Lets you brake hard without losing steering control
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C.
Means you don't have to use safe driving techniques
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D.
Eliminates the need to inspect brakes
Correct answer: B.
ABS preserves steering during emergency braking but does not shorten stopping distance.
Question 3 of 25 · Testing
When taking the road test, you will be expected to:
-
A.
Demonstrate the basic control skills only
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B.
Drive only on the highway
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C.
Show that you can perform safely in normal traffic
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D.
Drive only in residential areas
Correct answer: C.
The road test evaluates safe performance in actual traffic conditions.
Question 4 of 25 · Testing
The road test will be scored on:
-
A.
How fast you complete the route
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B.
Vehicle inspection, basic control, and on-road driving
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C.
Whether you wear a uniform
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D.
Your appearance
Correct answer: B.
You'll be evaluated on inspection skills, basic control skills, and safe on-road driving performance.
Question 5 of 25 · Inspection
What is the most important reason for doing a vehicle inspection?
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A.
To meet DOT requirements
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B.
Safety for yourself and others
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C.
To save fuel
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D.
To avoid roadside inspections
Correct answer: B.
Safety is the most important reason. A defective vehicle puts you, your cargo, and others at risk.
Question 6 of 25 · Basic Control
Where should the wheel chocks be placed?
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A.
Behind one tire
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B.
In front of and behind tires on the same axle
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C.
Only when on a hill
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D.
Both front and rear tires of the steer axle
Correct answer: B.
Place chocks both in front of and behind the wheels to prevent the vehicle from rolling either way.
Question 7 of 25 · Emergency Maneuvers
Controlled braking is:
-
A.
Pressing the brake to the floor and holding
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B.
Applying brakes hard enough to lock the wheels
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C.
Applying brakes to keep wheels just short of locking
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D.
Releasing brakes and coasting
Correct answer: C.
Controlled braking applies the brake firmly without locking the wheels, keeping the steering straight.
Question 8 of 25 · CDL Rules
Drivers convicted of driving a CMV without a valid CDL face:
-
A.
No fines for the first offense
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B.
Civil penalties up to $5,000 and possible jail time
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C.
Only a warning
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D.
A 30-day driving restriction
Correct answer: B.
Driving without a valid CDL can lead to significant federal civil penalties and possible criminal penalties.
Question 9 of 25 · Driver Wellness
Which of the following is NOT a sign of fatigued driving?
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A.
Frequent yawning
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B.
Drifting from your lane
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C.
Rapid blinking and clear focus
-
D.
Missing exits or traffic signs
Correct answer: C.
Rapid blinking with clear focus is not a fatigue sign. Yawning, drifting, and missing exits all are.
Question 10 of 25 · Adverse Conditions
Hydroplaning is most likely to occur when:
-
A.
Tires are properly inflated
-
B.
Speed is below 30 mph
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C.
Roads are dry
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D.
Tires lose contact with the road on wet pavement
Correct answer: D.
Hydroplaning happens when water builds up between the tire and the road, causing loss of contact.
Question 11 of 25 · Inspection
When inspecting your vehicle, the engine should be:
-
A.
Running with the hood open
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B.
Off, with the parking brake set, before starting checks under the hood
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C.
Idling in gear
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D.
Warm but turned off only on hills
Correct answer: B.
Set the parking brake, turn off the engine, and chock the wheels before checking under the hood.
Question 12 of 25 · Inspection
The proper way to test the service brake on a vehicle is to:
-
A.
Pump the pedal three times
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B.
Push the brake pedal firmly while moving about 5 mph
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C.
Put the parking brake on
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D.
Listen for air leaks
Correct answer: B.
Move the vehicle forward at about 5 mph and apply the brake firmly. The vehicle should not pull to either side.
Question 13 of 25 · Inspection
When should you stop and check your tires after starting a long trip?
-
A.
After 250 miles
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B.
Within the first 50 miles, then every 150 miles or 3 hours
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C.
Only when you stop for fuel
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D.
Tires don't need to be checked once you're moving
Correct answer: B.
Stop after the first 50 miles to check tires, then re-check every 150 miles or three hours.
Question 14 of 25 · Cargo
Which is correct about cargo and weight balance?
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A.
Heavy cargo should always be at the rear
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B.
Cargo should be balanced and secured to prevent shifting
-
C.
Side-to-side balance does not matter
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D.
Top-heavy loads improve stability
Correct answer: B.
Cargo must be evenly balanced and well secured. Top-heavy loads increase rollover risk.
Question 15 of 25 · Mountain Driving
What may happen if you don't shift gears properly when going up a hill?
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A.
You will use less fuel
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B.
The transmission will be damaged
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C.
You may lose control on a downgrade
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D.
Engine RPM will be too low
Correct answer: C.
Improper gear use can result in losing control of speed, especially on the way back down a hill.
Question 16 of 25 · Driver Wellness
Aggressive drivers should be:
-
A.
Confronted
-
B.
Reported and given plenty of room
-
C.
Followed closely
-
D.
Passed quickly without signaling
Correct answer: B.
Stay clear of aggressive drivers and report dangerous behavior to authorities.
Question 17 of 25 · Emergency Maneuvers
What should you do if your brakes fail on a downgrade?
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A.
Pump the brakes vigorously
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B.
Look for an escape ramp or open area to slow down
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C.
Shift into neutral
-
D.
Turn off the engine
Correct answer: B.
If brakes fail, look for an escape ramp or a route that will slow your vehicle without endangering others.
Question 18 of 25 · Driver Wellness
You should not eat or drink while driving because:
-
A.
It is illegal in all states
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B.
Spills can distract you
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C.
You should not put both hands on the wheel
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D.
It might damage the vehicle
Correct answer: B.
Eating and drinking divert attention and create spill hazards.
Question 19 of 25 · Communication
Communicating your intentions means:
-
A.
Honking before each turn
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B.
Using turn signals, brake lights, and the horn appropriately
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C.
Flashing high beams at all drivers
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D.
Hand signals only at intersections
Correct answer: B.
Use signals, brake lights, and the horn properly to communicate. Hand signals supplement them.
Question 20 of 25 · Emergency Maneuvers
Stab braking is used:
-
A.
Only on slippery roads
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B.
When you must stop quickly with non-ABS brakes
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C.
Whenever you stop
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D.
Only on downgrades
Correct answer: B.
Stab braking is an emergency technique used with non-ABS brakes: apply brakes fully, release when wheels lock, then reapply.
Question 21 of 25 · Inspection
Vehicle inspection is important because:
-
A.
Federal and state laws require it
-
B.
Safety is at risk
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C.
Defects can save lives if found early
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D.
All of the above
Correct answer: D.
Inspections are legally required and prevent breakdowns and crashes by catching defects early.
Question 22 of 25 · Backing
Which of these statements about backing a heavy vehicle is true?
-
A.
Back in a curved path whenever possible
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B.
Avoid backing whenever you can
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C.
Back as quickly as possible
-
D.
Use only the right mirror
Correct answer: B.
Avoid backing whenever you can. Park where you will be able to pull forward to leave.
Question 23 of 25 · Inspection
Pre-trip inspection of the vehicle should be done in the same order each time so that you:
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A.
Will look professional to other drivers
-
B.
Will learn it well and not skip anything
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C.
Can finish faster
-
D.
Pass the test more easily
Correct answer: B.
Following the same order helps prevent missed steps and builds reliable habits.
Question 24 of 25 · Backing
You should always try to park:
-
A.
So that you will have to back when leaving
-
B.
So that you can pull forward when leaving
-
C.
On the right shoulder of any highway
-
D.
Without using the parking brake
Correct answer: B.
Park so that you can pull forward to leave. Backing should always be avoided when possible.
Question 25 of 25 · Inspection
What is the minimum tread depth for non-steering axle tires?
-
A.
1/32 inch
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B.
2/32 inch
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C.
4/32 inch
-
D.
6/32 inch
Correct answer: B.
Federal regulations require at least 2/32 inch on non-steering tires.
About the General Knowledge Test
The General Knowledge test covers safe vehicle inspection, basic vehicle control, shifting gears, communicating, controlling speed, controlling distance, seeing hazards, distracted driving, aggressive drivers, communicating with other drivers, night driving, driving in fog, winter driving, hot weather driving, mountain driving, driving emergencies, anti-lock braking systems, skid recovery, accident procedures, fires, alcohol and other drugs, hazardous materials awareness, and staying alert and fit to drive. Every commercial driver in the United States must pass this test before any other CDL endorsement can be added.
The Colorado Division of Motor Vehicles administers this knowledge test as part of its commercial driver license program. To earn the CDL General Knowledge on your Colorado CDL, you need to score at least 40 out of 50 on the official version.
Topics covered on this practice test
- Inspection: 7 questions
- Emergency Maneuvers: 3 questions
- Driver Wellness: 3 questions
- Testing: 2 questions
- Backing: 2 questions
- Emergency Equipment: 1 question
- ABS: 1 question
- Basic Control: 1 question
- CDL Rules: 1 question
- Adverse Conditions: 1 question
- Cargo: 1 question
- Mountain Driving: 1 question
- Communication: 1 question
How to use this practice test
- Read each question carefully. CDL questions are written precisely — small wording differences matter.
- Click "Show Answers & Explanations" only after answering every question. Don't peek mid-test.
- Read the explanation for every question, even ones you got right. The reasoning is more important than the answer.
- Repeat the test until you score 100%. The questions are deterministic per state, so you can track your improvement over multiple sessions.
- Move on to the other endorsement tests for Colorado until you're ready for the official exam.
Tips specific to the General Knowledge test
The General Knowledge test is the foundation of every CDL. Topics include vehicle inspection, basic control, shifting, communicating, controlling speed, controlling space, hazard perception, distracted driving, night driving, fog, winter, hot weather, mountain driving, emergencies, anti-lock brakes, skid recovery, accident procedures, fires, alcohol, hazardous materials awareness, and staying alert. Most failures come from speeding through inspection-related questions; slow down and read carefully.
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