You are checking your steering and exhaust system during a pre-trip inspection. Which of these problems, if found, should be fixed before the vehicle is driven?

A small leak of power steering fluid

Steering wheel play of more than 10 degrees

Which of the following do you NOT have to do during the in-cab inspection?

Check that the steps leading to the cab entry are solid, clear of objects, and securely bolted to the frame.

Put the gear shift in neutral (for a manual) or park (for an automatic).

Make sure the parking brake is on.

Start the engine and listen for unusual noises.

Release the truck or tractor parking brake and apply _________. Try to pull forward gently. The vehicle should not move.

the four-way emergency flashers

When should you test your parking brake?

While the parking brake is applied

While your vehicle is moving at a very low speed

While your vehicle is moving at a speed of at least 10 mph

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20 questions
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District of Columbia CDL: Pre-Trip Inspection Practice Test

20 pre-trip inspection questions for the District of Columbia CDL Knowledge Test, out of 91 in the app. Answer each to see whether you got it right and why. The real District of Columbia Pre-Trip Inspection test has 20 questions and you need 16 correct (80%) to pass.

Facts updated Oct 26, 2026
Official source: law.cornell.edu
Independent, not affiliated with the DMV. How we write our questions

How it works

1Pick an answer20 questions, one tap each.
2See the ruleRight or wrong, every answer is explained.
3Get your scoreCompared with the real 80% pass mark.

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0/20 answered0 correctPass mark 80%

1Question 1 of 20
While you're performing the pre-trip inspection, where should the ignition key be?
Not quite. The answer is In your pocket
While you are performing the pre-trip inspection, you do not want someone (such as a co-driver) who is unaware of your location to start your vehicle and accidentally injure you. Make sure you have the ignition key with you as you perform the inspection.
2Question 2 of 20
If this is damaged, it could lead to a loss of the tire or loss of the wheel from the axle. Check that there is no damage and that there are no welding repairs. What are you inspecting?
Not quite. The answer is Rim
The rim is the outer part of the wheel, to which a tire is attached. A damaged rim can result in loss of the tire from the rim, loss of the wheel from the axle, loss of air pressure in the tire, or the wheel rolling off the rim because of damage to the flange. During your pre-trip inspection, check that the rim is undamaged and the flange isn't bent. Check that no welding repairs have been made to the rim. Finally, check that there are no rust trails (which might indicate that the rim is loose on the wheel).
3Question 3 of 20
Which of these keeps your vehicle from rolling when it's parked?
Not quite. The answer is Parking brake
The parking brake keeps your vehicle from moving when it's parked. The mechanism is separate from the service brakes that you use in normal driving.
4Question 4 of 20
________ are gas or hydraulic devices that cushion the vehicle's ride and stabilize the vehicle.
Not quite. The answer is Shock absorbers
During your pre-trip inspection, check the shock absorbers on every axle of your vehicle (including the trailers if any) to be sure that they are securely mounted and not leaking.
5Question 5 of 20
You are checking your steering and exhaust system during a pre-trip inspection. Which of these problems, if found, should be fixed before the vehicle is driven?
Not quite. The answer is Both of the above
Your steering system is critical to your safety, especially in an emergency. Excessive steering wheel play may make it difficult for you to know which way your front wheels are pointed. A leak of power steering fluid may eventually lead to power steering failure if left uncorrected.
6Question 6 of 20
Which tires should have a minimum tread depth of 2/32 inch?
Not quite. The answer is Non-steering axle tires
Steering axle tires must have a tread depth of at least 4/32 inch. All other tires must have a tread depth of at least 2/32 inch.
7Question 7 of 20
What system consists of external piping for conducting combustion gases from the engine?
Not quite. The answer is Exhaust
Your vehicle's exhaust system consists of a set of pipes and other components for removing the hot combustion gases produced by your engine. One of these gases, carbon monoxide (CO), can be particularly poisonous to you if an exhaust leak causes CO to build up in the cab. During your pre-trip inspection, check the exhaust system for cracks, holes, and severe dents. Check for sounds and signs of leaks. There should be no loose, broken, or missing parts. No exhaust system parts should be rubbing against fuel system parts, tires, wires, air lines, or other moving parts of the vehicle.
8Question 8 of 20
Which of the following do you NOT have to do during the in-cab inspection?
Not quite. The answer is Check that the steps leading to the cab entry are solid, clear of objects, and securely bolted to the frame.
During the in-cab inspection, shift into neutral (for a manual) or park (for an automatic) and make sure the parking brake is on. Start the engine and listen for unusual noises. (You do inspect the steps to the cab during the pre-trip inspection, but not during the in-cab inspection.)
9Question 9 of 20
Release the truck or tractor parking brake and apply _________. Try to pull forward gently. The vehicle should not move.
Not quite. The answer is the trailer parking brake
Even after you release the truck or tractor parking brake, the trailer parking brake should still hold your vehicle in place when you try to pull forward gently.
10Question 10 of 20
When should you test your parking brake?
Not quite. The answer is While the parking brake is applied
The parking brake is meant to keep your vehicle from moving. The best way to test it is to apply the parking brake and then try to pull forward gently. The parking brake should hold your vehicle in place. If you're pulling one or more trailers, test each trailer's parking brakes in the same way.
11Question 11 of 20
Which tires should have a minimum tread depth of 4/32 inch?
Not quite. The answer is Steering axle tires
The tires on the steering axle should have at least 4/32 inch of tread, and all other tires should have at least 2/32 inch of tread. Inadequate tread on the front tires increases the risk of a front-wheel skid.
12Question 12 of 20
During your inspection, checking which of these will NOT help prevent a vehicle fire?
Not quite. The answer is Battery fluid level
There are many possible causes of vehicle fires, including poor cargo ventilation and electrical short circuits caused by damaged insulation or loose connections. A low battery fluid level can impair battery performance and even damage the battery, but it's unlikely to cause a fire.
13Question 13 of 20
Apply _________ and then try to pull forward gently. If it works properly, your vehicle shouldn't move.
Not quite. The answer is the parking brake
The parking brake is meant to keep your vehicle from moving. The best way to test it is to apply the brake and then try to pull forward gently. The parking brake should hold your vehicle in place.
14Question 14 of 20
_________ are the brackets, bolts, or bushings that are used to attach the spring or air bag to the axle and vehicle frame.
Not quite. The answer is Spring mounts
Spring mounts consist of the brackets, bolts, shackles, and bushings used for attaching springs or air bags (for an air ride suspension) to the vehicle frame. During your inspection, check that the spring mounts are secured to the vehicle's frame and axles. Check that no bushings are damaged or missing. Check that there are no broken, loose, or missing bolts or U-bolts.
15Question 15 of 20
When inspecting the header board, make sure it is
Not quite. The answer is secure and undamaged.
A front-end header board is located at the front part of a trailer. The header board prevents cargo from moving forward (and possibly injuring you) in the event of a crash or sudden stop. Check to make sure that the header board is secure, upright, undamaged (no dents, no corrosion, no missing rivets, etc.), and strong enough to prevent the cargo from moving forward past it.
16Question 16 of 20
Make sure that the _________ are not cut, chafed, spliced, or worn, and not tangled, pinched, or dragged against tractor parts.
Not quite. The answer is air lines and electrical lines
During your pre-trip inspection, check the electrical lines and air hoses (or hydraulic hoses for hydraulic brakes). Make sure that the lines and hoses are not cut, chafed, spliced, or worn. Also make sure they are not tangled, pinched, or dragging on parts of the tractor.
17Question 17 of 20
Which of the following is a way to check the coolant level?
Not quite. The answer is Check the sight glass.
Your vehicle may provide a way for you to check the coolant level even when the engine is hot. Such devices include reservoir sight glasses, see-through coolant overflow containers, and coolant recovery containers.
18Question 18 of 20
You are checking for damage to the longitudinal members, cross members, box, or floor. What are you inspecting?
Not quite. The answer is Frame
The frame consists of the structural members for supporting the body of the vehicle or trailer. When inspecting the frame, (1) check for cracks; (2) check for broken welds; and (3) check for illegal holes or other damage to the longitudinal frame members, cross members, box, or floor.
19Question 19 of 20
What do you inspect to make sure that all are present and show no signs of looseness such as rust trails or shiny threads?
Not quite. The answer is Lug nuts
During your pre-trip inspection, check that all lug nuts are present and accounted for, tightly fastened, and free of cracks or distortions.
20Question 20 of 20
What releases the fifth wheel locking jaws so the trailer can be coupled?
Not quite. The answer is Release arm
The release arm allows you to disengage the fifth-wheel locking jaws so you can uncouple the trailer. During your pre-trip inspection, check that the release arm is in the engaged position and the safety latch (if so equipped) is in place.

Questions people ask

Is this District of Columbia CDL: Pre-Trip Inspection Practice Test like the real District of Columbia CDL Knowledge Test?

The questions are written in the same style as the real test, from official sources, with an explanation for each answer. The real test has 20 questions; this free test has 20.

How many questions are on the District of Columbia CDL Knowledge Test?

The General Knowledge test has 20 questions. Each class and endorsement adds its own test.

What score do you need to pass the District of Columbia CDL Knowledge Test?

You need 16 out of 20 correct (80%).

How old do you have to be to take the District of Columbia CDL Knowledge Test?

You can take it from age 18.

Where can I practice more questions?

The Driving Exam Prep app has the full question bank for your test, a step-by-step roadmap, a mistakes review and a readiness score against the real pass mark.

Official sources

Our questions are written from these official sources. Always study your official handbook too: rules change, and our practice questions may differ from your real test.

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While you're performing the pre-trip inspection, where should the ignition key be?

If this is damaged, it could lead to a loss of the tire or loss of the wheel from the axle. Check that there is no damage and that there are no welding repairs. What are you inspecting?

Which of these keeps your vehicle from rolling when it's parked?

________ are gas or hydraulic devices that cushion the vehicle's ride and stabilize the vehicle.

You are checking your steering and exhaust system during a pre-trip inspection. Which of these problems, if found, should be fixed before the vehicle is driven?

Which tires should have a minimum tread depth of 2/32 inch?

What system consists of external piping for conducting combustion gases from the engine?

Which of the following do you NOT have to do during the in-cab inspection?

Release the truck or tractor parking brake and apply _________. Try to pull forward gently. The vehicle should not move.

When should you test your parking brake?

Which tires should have a minimum tread depth of 4/32 inch?

During your inspection, checking which of these will NOT help prevent a vehicle fire?

Apply _________ and then try to pull forward gently. If it works properly, your vehicle shouldn't move.

_________ are the brackets, bolts, or bushings that are used to attach the spring or air bag to the axle and vehicle frame.

When inspecting the header board, make sure it is

Make sure that the _________ are not cut, chafed, spliced, or worn, and not tangled, pinched, or dragged against tractor parts.

Which of the following is a way to check the coolant level?

You are checking for damage to the longitudinal members, cross members, box, or floor. What are you inspecting?

What do you inspect to make sure that all are present and show no signs of looseness such as rust trails or shiny threads?

What releases the fifth wheel locking jaws so the trailer can be coupled?

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Questions people ask

Official sources

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