CDL General Knowledge Practice Test

25 practice questions

Choose an answer, then check it under Show answer.

1. Question 1 of 25Medium

   Why should trip entries list every state or province the vehicle traveled through, even those with only a few miles?

   1. AA. Because a trip permit is required for every jurisdiction entered
   2. BB. Because each jurisdiction issues a separate registration cab card
   3. CC. Because fuel prices may change from one jurisdiction to the next
   4. DD. Because fees and taxes are owed to every jurisdiction operated in
   Show answer to question 1

   Answer: D. Because fees and taxes are owed to every jurisdiction operated in

   The IVDR is the source document for the fees and taxes payable to the jurisdictions in which the vehicle is operated, so each one traveled through must appear on the record. Cab cards, fuel prices and trip permits are not the reason given for listing every jurisdiction.

2. Question 2 of 25Easy

   After successfully passing the vehicle inspection segment of the CDL skills test, which segment must the applicant take next?

   1. AA. Combination vehicle coupling
   2. BB. On-road driving
   3. CC. Basic vehicle control
   4. DD. Air brake pressure test
   Show answer to question 2

   Answer: C. Basic vehicle control

   The manual states that the skills test segments must be taken in the order listed: vehicle inspection, basic vehicle control, and on-road driving. Basic vehicle control is the second segment and immediately follows the vehicle inspection. On-road driving is incorrect because it is the final segment and can only be taken after basic vehicle control is completed successfully.

3. Question 3 of 25Medium

   When preparing a route before a trip to prevent drowsiness, what should a driver identify?

   1. AA. Total distance, stopping points, and logistic considerations
   2. BB. Minimum speed limits, passing lanes, and low-traffic detours
   3. CC. Alternative unpaved routes, scenic areas, and local taxes
   4. DD. Roadside repair shops, dispatch centers, and weigh scales
   Show answer to question 3

   Answer: A. Total distance, stopping points, and logistic considerations

   The manual recommends preparing the route carefully to identify total distance, stopping points, and other logistic considerations. The other options list factors unrelated to pre-trip planning for fatigue prevention.

4. Question 4 of 25Medium

   After you have steered around an object in your path, what should you be ready to do?

   1. AA. Apply the brakes very firmly
   2. BB. Accelerate to regain road speed
   3. CC. Shift the transmission to neutral
   4. DD. Counter-steer in the other direction
   Show answer to question 4

   Answer: D. Counter-steer in the other direction

   The manual says to be prepared to counter-steer, turning the wheel back the other way, once you have passed whatever was in your path. Applying the brakes firmly at that point is not the corrective steering action described.

5. Question 5 of 25Medium

   Why is the road especially slippery just after it starts to rain?

   1. AA. Water mixes with oil left by vehicles.
   2. BB. Water on the pavement freezes instantly.
   3. CC. Tires are colder and lose flexibility.
   4. DD. The rain immediately washes all oil away.
   Show answer to question 5

   Answer: A. Water mixes with oil left by vehicles.

   Right after rain begins, water mixes with oil left on the road by vehicles, making the surface very slippery. The oil is washed away only if the rain continues.

6. Question 6 of 25Medium

   What can happen as a result of delayed decision making and improper action caused by driver distraction?

   1. AA. Mechanical components in the steering gear will bind and lock up
   2. BB. Automatic emergency systems will cut all fuel flow to the engine
   3. CC. Electronic safety controls will permanently disable vehicle power
   4. DD. The driver may make incorrect inputs to steering, fuel, or brakes
   Show answer to question 6

   Answer: D. The driver may make incorrect inputs to steering, fuel, or brakes

   Delayed decision making and improper action can cause a distracted driver to apply incorrect inputs to the steering, accelerator, or brakes. Distraction impairs human judgment and control rather than triggering sudden mechanical locks or automated vehicle shutdowns.

7. Question 7 of 25Easy

   A driver turns the steering wheel more sharply than the vehicle can turn. What is this mistake called?

   1. AA. Over-braking
   2. BB. Over-steering
   3. CC. Driving too fast for conditions
   4. DD. Over-acceleration
   Show answer to question 7

   Answer: B. Over-steering

   Over-steering means turning the wheels more sharply than the vehicle can turn, and it is one of the four causes of skids. Over-braking and over-acceleration are different mistakes that lock the wheels or spin the drive wheels.

8. Question 8 of 25Medium

   After you avoid eye contact with an aggressive driver, what is the next recommended action?

   1. AA. Make eye contact to show you are calm.
   2. BB. Report the driver to the authorities.
   3. CC. Speed up to hold your position in the lane.
   4. DD. Ignore gestures and refuse to react to them.
   Show answer to question 8

   Answer: D. Ignore gestures and refuse to react to them.

   The steps list avoiding eye contact and then ignoring gestures and refusing to react to them. Reporting the driver comes after those steps, and making eye contact is something to avoid.

9. Question 9 of 25Hard

   The Motor Carrier Safety Improvement Act of 1999 requires a CDL holder to be disqualified from operating a commercial motor vehicle for which situation?

   1. AA. Conviction of certain moving violations in your personal vehicle
   2. BB. Holding a mobile telephone to make a voice call while driving
   3. CC. Holding a commercial driver's license from more than one state
   4. DD. Failure to wear a safety belt while operating a commercial vehicle
   Show answer to question 9

   Answer: A. Conviction of certain moving violations in your personal vehicle

   The manual says the Motor Carrier Safety Improvement Act of 1999 requires a CDL holder to be disqualified for certain moving violations committed in a personal vehicle. The other choices describe prohibited acts, but they are not the MCSIA requirement described in the excerpt.

10. Question 10 of 25Hard

    A driver must stop on a two-lane road just beyond a curve and places the rearmost warning device 100 feet behind the vehicle. The curve blocks the device from view. What should the driver do?

    1. AA. Place another device 10 feet ahead of the vehicle.
    2. BB. Move the rearmost device back beyond the curve.
    3. CC. Move the rearmost device to the front corner.
    4. DD. Leave the device and turn on the taillights.
    Show answer to question 10

    Answer: B. Move the rearmost device back beyond the curve.

    If a hill, curve, or other obstruction prevents other drivers from seeing the vehicle within 500 feet, the manual says to move the rear-most triangle back down the road so warning is provided. A device hidden by the curve does not warn approaching drivers.

11. Question 11 of 25Easy

    What hazard must you keep in mind when viewing surrounding traffic through a curved (convex) mirror?

    1. AA. Roadway markings appear reversed from left to right.
    2. BB. Approaching vehicles seem farther away than they really are.
    3. CC. Passing vehicles seem to move at double their actual speed.
    4. DD. Nearby vehicles look larger than they actually are.
    Show answer to question 11

    Answer: B. Approaching vehicles seem farther away than they really are.

    In convex mirrors, images appear smaller, which causes objects and other vehicles to seem farther away than they really are. Drivers who misjudge this distance might attempt an unsafe maneuver, wrongly assuming they have more clearance than exists.

12. Question 12 of 25Medium

    You are involved in a crash on a busy road, and your truck can still be driven. What should you try to do with your vehicle?

    1. AA. Leave it in the traffic lane until officers arrive.
    2. BB. Stop it in the road and put out triangles.
    3. CC. Move it to the side of the road.
    4. DD. Park it in the nearest service station.
    Show answer to question 12

    Answer: C. Move it to the side of the road.

    If your vehicle is involved and can be moved, the manual says to try to get it to the side of the road. Leaving it in the lane blocks traffic and makes another crash more likely.

13. Question 13 of 25Easy

    When driving in winter conditions, which highway maintenance vehicles should you watch for and give plenty of room?

    1. AA. Asphalt rollers, crack sealers, and patch trucks
    2. BB. Flatbed wreckers, tow trucks, and service vans
    3. CC. Snowplows, salt trucks, and sand trucks
    4. DD. Road sweepers, paint trucks, and attenuators
    Show answer to question 13

    Answer: C. Snowplows, salt trucks, and sand trucks

    The CDL manual instructs drivers to watch for snowplows, as well as salt and sand trucks, and give them plenty of room. Road sweepers and paint trucks are common highway maintenance vehicles, but they are not the specific winter maintenance vehicles identified for winter driving.

14. Question 14 of 25Hard

    On a long downgrade, how should engine braking and the brakes be used in the proper procedure?

    1. AA. Use engine braking only after the brakes begin to fade.
    2. BB. Use engine braking as the principal control and the brakes as a supplement.
    3. CC. Use the brakes as the principal control and engine braking as a supplement.
    4. DD. Use the brakes continuously and avoid engine braking.
    Show answer to question 14

    Answer: B. Use engine braking as the principal control and the brakes as a supplement.

    The engine's braking effect should be the main way you control speed, with the brakes used only to supplement it. Relying on the brakes as the main control can overheat them and cause fade.

15. Question 15 of 25Hard

    Why is a cracked or damaged spring hanger considered a critical defect?

    1. AA. It prevents the driver from measuring tire air pressure
    2. BB. It forces dual tires to rotate at different speeds
    3. CC. It stops the electrical connections from reaching the trailer
    4. DD. It allows the axle to move out of its proper position
    Show answer to question 15

    Answer: D. It allows the axle to move out of its proper position

    Spring hangers secure suspension springs to the frame and maintain axle alignment, so cracked or broken hangers can allow the axle to shift out of place. Dual tires are mounted together on the same wheel hub and rotate at the same speed regardless of spring hanger condition.

16. Question 16 of 25Easy

    What risk do non-prescription cold medicines pose to a commercial driver?

    1. AA. They permanently damage night vision after a single daytime dose.
    2. BB. They can cause drowsiness and impair safe driving performance.
    3. CC. They can cause sudden mechanical failures in power steering.
    4. DD. They trigger false positive readings on vehicle emissions tests.
    Show answer to question 16

    Answer: B. They can cause drowsiness and impair safe driving performance.

    Over-the-counter drugs such as cold remedies can make a driver drowsy or otherwise degrade safe driving ability. Common cold medicines do not damage night vision permanently or affect vehicle systems.

17. Question 17 of 25Medium

    A driver is preparing to park a commercial vehicle for the night. According to basic vehicle control rules, how should the vehicle be parked?

    1. AA. With the front wheels turned sharply toward oncoming traffic.
    2. BB. In reverse against a curb to avoid blocking any travel lanes.
    3. CC. Angled to the right side so mirrors capture traffic clearly.
    4. DD. In a position that allows the driver to pull forward when leaving.
    Show answer to question 17

    Answer: D. In a position that allows the driver to pull forward when leaving.

    Because backing is always dangerous and a driver cannot see everything behind the vehicle, backing should be avoided whenever possible. The CDL manual instructs drivers to park so they will be able to pull forward when leaving. Backing into tight or blind positions upon departure greatly increases the risk of a collision.

18. Question 18 of 25Medium

    Why does the presence of double tracks at a grade crossing require commercial drivers to perform a double check?

    1. AA. A train traveling on one track may hide an approaching train on the other track.
    2. BB. Active warning signals shut down automatically once the first train passes.
    3. CC. Railroad rules require trailing trains to follow closely without sounding horns.
    4. DD. Trains on adjacent tracks are permitted to travel at twice the posted track speed.
    Show answer to question 18

    Answer: A. A train traveling on one track may hide an approaching train on the other track.

    The CDL manual explains that double tracks require a double check because a train on one track may hide another approaching train on the second track. Drivers must wait until the crossing is completely clear and verify no other trains are near before moving. Believing that warning signals shut down immediately is incorrect, as active signals remain engaged whenever any train approaches.

19. Question 19 of 25Hard

    A driver transports freight entirely between two cities within the same state, but the cargo originated in another state. Why is this trip classified as interstate commerce?

    1. AA. The route utilizes highways receiving federal transportation funding.
    2. BB. Any point-to-point delivery between cities is considered interstate.
    3. CC. The cargo is part of a trip that began in another state.
    4. DD. Commercial motor vehicles are always subject to interstate regulations.
    Show answer to question 19

    Answer: C. The cargo is part of a trip that began in another state.

    Interstate commerce includes driving between two places within a single state when the cargo or passengers are part of a trip that began or will end in another state or foreign country. Operating between two in-state points does not automatically become interstate unless the cargo, passengers, or vehicle route crosses into another state or country.

20. Question 20 of 25Medium

    What shifting method involves allowing the engine rpm to reach higher levels before each shift as the driver moves up through the gears?

    1. AA. Progressive shifting
    2. BB. Auxiliary shifting
    3. CC. Double clutching
    4. DD. Split shifting
    Show answer to question 20

    Answer: A. Progressive shifting

    Progressive shifting is the technique where the engine rpm at which you shift up becomes higher as you advance into higher gears. Double clutching refers to releasing and depressing the clutch pedal between neutral and gear positions, rather than raising shift points progressively.

21. Question 21 of 25Easy

    What do placards displayed on the outside of a vehicle identify?

    1. AA. The hazard class of the cargo being carried
    2. BB. The registered gross weight of the vehicle
    3. CC. The delivery route assigned to the driver
    4. DD. The inspection status of the trailer
    Show answer to question 21

    Answer: A. The hazard class of the cargo being carried

    Placards are signs put on the outside of a vehicle that identify the hazard class of the cargo, and a placarded vehicle must have at least four identical placards on the front, rear, and both sides. The vehicle's registered weight appears on registration documents, not on placards, so that option is wrong.

22. Question 22 of 25Medium

    Your cargo is stacked so that you cannot see the traffic on either side of your vehicle. What must you do?

    1. AA. Keep the load and drive only on rural roads.
    2. BB. Keep the load if you use your mirrors instead.
    3. CC. Rearrange the load so your view is not blocked.
    4. DD. Keep the load if it is properly tied down.
    Show answer to question 22

    Answer: C. Rearrange the load so your view is not blocked.

    The CDL manual says you are responsible for knowing your cargo does not obscure your view ahead or to the sides. Good tiedowns do not fix a blocked view, because the driver still cannot see traffic beside the vehicle.

23. Question 23 of 25Easy

    Before you start across a road in a loaded truck, what should you make sure of?

    1. AA. That your trailer brakes have fully released.
    2. BB. That you can get all the way across before traffic reaches you.
    3. CC. That the vehicle behind you has come to a stop.
    4. DD. That your turn signal is still flashing.
    Show answer to question 23

    Answer: B. That you can get all the way across before traffic reaches you.

    The manual says to make sure you can get all the way across the road before traffic reaches you. A large vehicle is slow to clear an intersection, so starting across without enough room leaves you in the path of approaching traffic.

24. Question 24 of 25Hard

    Your vehicle has a see-through coolant overflow container that is not part of the pressurized system. The engine is at operating temperature and the coolant level is low. What can you do?

    1. AA. Remove the radiator cap first, then fill the overflow container.
    2. BB. Add coolant only after releasing pressure from the radiator.
    3. CC. Remove the container cap and add coolant while the engine is hot.
    4. DD. Wait until the engine is completely cold before adding any coolant.
    Show answer to question 24

    Answer: C. Remove the container cap and add coolant while the engine is hot.

    The manual says that when the container is not part of the pressurized system, its cap can be safely removed and coolant added even when the engine is at operating temperature. Waiting for a cold engine is unnecessary in this case, and the radiator cap should never be removed while the system is hot.

25. Question 25 of 25Hard

    You drive a straight truck that has working ABS on all axles and you need to make an emergency stop. How should you brake?

    1. AA. Fully apply the brakes
    2. BB. Pump the brake pedal rapidly
    3. CC. Apply light pressure and coast to a stop
    4. DD. Use the parking brake with the service brakes
    Show answer to question 25

    Answer: A. Fully apply the brakes

    The CDL manual says you normally brake as you always have, with one exception: with working ABS on all axles of a straight truck or combination, you can fully apply the brakes in an emergency stop. Pumping the pedal is wrong because ABS already works far faster than the driver can respond to wheel lockup.

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