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Alabama CDL — General Knowledge Practice Test

50 questions · pass with 40 correct. You get instant feedback and an explanation after every answer.

Alabama CDL — General Knowledge questions with answers

20 sample questions from the Alabama CDL — General Knowledge question bank — each with the correct answer, a short explanation, and the section of the official handbook it comes from.

  1. 1. As you pass through a work zone with a worker near the travel lane, you should:

    Correct answer: Decrease your speed even further

    Beyond obeying the posted limit, slow down more when workers are near the travel lane.

    Source: Alabama CDL Manual - Section 2.6.7 (Roadway Work Zones)

  2. 2. How many people must a vehicle be designed to carry before a CDL is required on that basis?

    Correct answer: 16 or more, including the driver

    A vehicle built to transport 16 or more people, counting the driver, requires a commercial license.

    Source: Alabama CDL Manual - Section 1 (Introduction - CMV Definitions)

  3. 3. A cross-buck sign at a railroad crossing tells drivers to:

    Correct answer: Yield the right of way to any approaching train

    The cross-buck marks the crossing and requires drivers to yield to trains; extra signs show the number of tracks.

    Source: Alabama CDL Manual - Section 2.15.2 (Warning Signs and Devices)

  4. 4. Below 40 mph, how much following distance does the manual suggest for the length of your vehicle?

    Correct answer: One second for every 10 feet of vehicle length

    Below 40 mph, count a second for each 10 feet your vehicle measures, then add one more second above that speed.

    Source: Alabama CDL Manual - Section 2.7.1 (Space Ahead)

  5. 5. In fog, which headlight setting should you generally use?

    Correct answer: Low beams

    High beams reflect off fog and worsen glare, so low beams give better visibility in fog.

    Source: Alabama CDL Manual - Section 2.12 (Driving in Fog)

  6. 6. Rental-truck drivers should be watched carefully because they:

    Correct answer: Are frequently unaccustomed to the big blind spots around a large vehicle

    People at the wheel of a rental truck are often not used to how little they can see to the sides and rear.

    Source: Alabama CDL Manual - Section 2.8.3 (Drivers Who Are Hazards)

  7. 7. A driver certified only for intrastate operation receives which restriction on the CDL?

    Correct answer: A restriction barring interstate operation

    Certifying as intrastate adds the K restriction, which prohibits operating the CMV in interstate commerce.

    Source: Alabama CDL Manual - Section 1 (Introduction - Restrictions)

  8. 8. A burning tire is best dealt with by:

    Correct answer: Cooling it with large amounts of water

    Because a tire holds heat, it must be cooled - often with lots of water - to keep it from reigniting.

    Source: Alabama CDL Manual - Section 2.21.3 (Fire Fighting)

  9. 9. The slow-moving vehicle emblem is described as:

    Correct answer: A red triangle with an orange center

    Farm and construction equipment often display a red triangle with an orange center to warn of their low speed.

    Source: Alabama CDL Manual - Section 2.8.3 (Drivers Who Are Hazards)

  10. 10. If you become too ill to drive safely, you should:

    Correct answer: Not drive, except to reach the nearest safe stopping point in an emergency

    When illness makes safe operation impossible you must not drive, other than reaching a safe place to stop in a true emergency.

    Source: Alabama CDL Manual - Section 2.22.3 (Illness)

  11. 11. When you set out warning triangles, you should hold each triangle:

    Correct answer: Between yourself and oncoming traffic so drivers can see you

    Keeping the triangle between you and approaching traffic makes you visible to other drivers while you place it.

    Source: Alabama CDL Manual - Section 2.7 (Managing Space - Stopping on the Road)

  12. 12. Why should you never try to race a train to a crossing?

    Correct answer: It is extremely hard to judge a train's speed

    A train's speed is very difficult to gauge, and racing one to the crossing is never worth the risk.

    Source: Alabama CDL Manual - Section 2.15.3 (Driving Procedures)

  13. 13. A single vehicle needs a commercial driver license once its gross vehicle weight rating reaches what figure?

    Correct answer: 26,001 pounds or more

    Any one vehicle rated at 26,001 pounds or above falls under the commercial category, so a CDL is required to drive it.

    Source: Alabama CDL Manual - Section 1 (Introduction - CMV Definitions)

  14. 14. On a trailer, a steady yellow ABS lamp on the left rear indicates:

    Correct answer: The trailer's antilock braking system is not working properly

    For trailers, a yellow ABS malfunction lamp on the left rear that stays on shows the antilock system needs attention.

    Source: Alabama CDL Manual - Section 2.1.5 (Seven-step Inspection Method)

  15. 15. About how far will a vehicle travel before stopping from 55 mph under ideal conditions?

    Correct answer: Roughly 419 feet

    Adding perception, reaction, and braking distance, a vehicle at 55 mph needs a minimum of about 419 feet to stop.

    Source: Alabama CDL Manual - Section 2.6.1 (Stopping Distance)

  16. 16. During the seven-step inspection, how should you begin checking the engine compartment?

    Correct answer: By confirming the parking brake is on and/or the wheels are chocked

    Before opening the hood you make sure the parking brake is set or the wheels are chocked so the vehicle cannot move.

    Source: Alabama CDL Manual - Section 2.1.5 (Seven-step Inspection Method)

  17. 17. When a driver is tailgating you, one thing you should NOT do is:

    Correct answer: Play tricks such as switching your taillights on or flicking your brake lights

    Tricks like flashing the brake lights can confuse a tailgater; instead stay steady, leave extra room ahead, and let them pass.

    Source: Alabama CDL Manual - Section 2.7.2 (Space Behind)

  18. 18. If federal or state inspectors judge your vehicle unsafe, they will:

    Correct answer: Place it out of service until repairs are made

    An unsafe vehicle is ordered out of service and may not be driven until the defect has been corrected.

    Source: Alabama CDL Manual - Section 2.1.1 (Why Inspect)

  19. 19. At an accident scene where you are not badly hurt, your first action should be to:

    Correct answer: Protect the area so another crash does not occur

    Protecting the scene - warning other traffic and preventing a second collision - comes before notifying authorities or aiding the injured.

    Source: Alabama CDL Manual - Section 2.20.1 (Protect the Area)

  20. 20. A sign below the cross-buck at a crossing that reads a number tells you:

    Correct answer: How many tracks the crossing has

    When more than one track is present, a small sign under the cross-buck shows the number of tracks to expect.

    Source: Alabama CDL Manual - Section 2.15.2 (Warning Signs and Devices)