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AK CDL General Knowledge study materials
AK CDL General Knowledge study resources

AK CDL General Knowledge practice questions

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Question 1Vehicle Inspection and Pre-Trip Procedures

What is the main purpose of a pre-trip inspection?

  1. To estimate the fuel cost for the planned route
  2. To calculate the cargo weight for the bill of lading
  3. To choose a route with fewer steep hills
  4. To find problems that could cause a crash or breakdown Correct answer.

Explanation

A pre-trip inspection is a safety check of the vehicle, cargo, and required equipment. Its purpose is to catch defects before they cause a crash or breakdown.

Question 2Vehicle Inspection and Pre-Trip Procedures

Which three parts make up a complete vehicle inspection?

  1. Cargo loading, cargo unloading, and freight billing
  2. Previous driver's report, walk-around inspection, and during-trip inspection Correct answer.
  3. Engine tune-up, tire rotation, and oil change
  4. Fueling, weighing, and route planning

Explanation

The inspection process includes reviewing the last driver's report, doing a walk-around inspection, and checking the vehicle during the trip. Each part helps catch defects at a different stage.

Question 3Vehicle Inspection and Pre-Trip Procedures

What is the minimum legal tread depth for front axle tires on a commercial motor vehicle?

  1. 4/32 inch Correct answer.
  2. 2/32 inch
  3. 6/32 inch
  4. 1/32 inch

Explanation

Front steer tires must have at least 4/32 inch of tread depth. All other tires on the vehicle must have at least 2/32 inch.

Question 4Vehicle Inspection and Pre-Trip Procedures

When checking engine oil, the vehicle should be on level ground and the engine should be:

  1. Shut off Correct answer.
  2. Running at high idle
  3. Warm and running
  4. Revved several times

Explanation

Oil drains back into the pan when the engine is off, so the dipstick reading is accurate. Checking on level ground also prevents a false reading.

Question 5Vehicle Inspection and Pre-Trip Procedures

Which group lists required emergency equipment for a commercial vehicle?

  1. Cell phone, GPS unit, and flashlight
  2. First aid kit, blankets, and drinking water
  3. Jack, lug wrench, and spare tire
  4. Fire extinguisher, warning triangles, and spare fuses Correct answer.

Explanation

Commercial vehicles must carry a fire extinguisher, warning devices such as triangles, and spare fuses unless the vehicle has circuit breakers. These items help in a breakdown or emergency.

Question 6Vehicle Inspection and Pre-Trip Procedures

How can a driver check that the brake lights and turn signals are working during a walk-around inspection?

  1. By watching the dashboard gauge
  2. By listening for a click from the relay
  3. By checking the fuse box only
  4. By using a helper or reflecting the lights off a wall Correct answer.

Explanation

The driver must see the lights operate, so a helper or a reflective surface is needed. A fuse box check does not prove the bulbs and wiring work.

Question 7Vehicle Inspection and Pre-Trip Procedures

During a trip, when should a driver check the cargo and the vehicle?

  1. After 50 miles, then every 150 miles or 3 hours Correct answer.
  2. Once every 500 miles
  3. Only when a dashboard warning light appears
  4. Only after reaching the final destination

Explanation

The CDL manual recommends a cargo and vehicle check after the first 50 miles. After that, checks should be made every 150 miles or every 3 hours.

Question 8Vehicle Inspection and Pre-Trip Procedures

What does excessive push rod travel on a slack adjuster indicate?

  1. The air compressor is overcharging
  2. The trailer is overloaded
  3. The brakes are out of adjustment Correct answer.
  4. The tires are underinflated

Explanation

Push rod travel is a measure of brake adjustment. Too much travel means the brake chamber has to push farther, so braking force may be reduced.

Question 9Vehicle Inspection and Pre-Trip Procedures

During an air brake check with the engine off, the low-pressure warning device should activate before pressure drops below:

  1. 90 psi
  2. 120 psi
  3. 60 psi Correct answer.
  4. 30 psi

Explanation

The warning buzzer or light must come on before air pressure falls below 60 psi. This gives the driver time to stop safely before brakes are lost.

Question 10Vehicle Inspection and Pre-Trip Procedures

When checking a fifth wheel coupling, the release lever safety latch should be:

  1. Tied back with wire
  2. Engaged over the release lever Correct answer.
  3. Removed for inspection
  4. Coated with grease

Explanation

The safety latch must close over the release lever to prevent accidental uncoupling. A missing or open latch is a serious defect.

Question 11Vehicle Inspection and Pre-Trip Procedures

How much steering wheel play is generally considered too much for a commercial vehicle?

  1. More than 45 degrees
  2. More than 2 degrees
  3. More than 10 degrees, or about 2 inches Correct answer.
  4. More than 5 degrees

Explanation

Steering wheel free play should not exceed about 10 degrees, which is roughly 2 inches at the rim. More play can make steering imprecise.

Question 12Vehicle Inspection and Pre-Trip Procedures

While inspecting the suspension, a driver finds a missing leaf in a leaf spring assembly. What should the driver do?

  1. Place the vehicle out of service until repaired Correct answer.
  2. Reduce speed and complete the trip
  3. Continue if the vehicle rides level
  4. Add a block to replace the leaf

Explanation

A missing leaf weakens the spring and can cause loss of control or axle damage. The vehicle should not be driven until the suspension is repaired.

Question 13Vehicle Inspection and Pre-Trip Procedures

Rust streaks around the lug nuts on a wheel may indicate:

  1. New tires
  2. A faulty speedometer
  3. Loose lug nuts Correct answer.
  4. Correctly torqued nuts

Explanation

Rust streaks from the nut holes can show that the nuts have moved. The driver should check torque and have the wheel inspected.

Question 14Vehicle Inspection and Pre-Trip Procedures

Where should a driver look for exhaust system leaks?

  1. Only at the tailpipe
  2. Inside the cab near the radio
  3. At the top of the engine only
  4. Under the vehicle along the pipe and muffler Correct answer.

Explanation

Exhaust leaks can occur anywhere along the system, including pipes, joints, and the muffler. The driver should inspect underneath the vehicle for soot, holes, and loose mounts.

Question 15Vehicle Inspection and Pre-Trip Procedures

When checking the coolant level, the driver should:

  1. Check the sight glass or reservoir when the engine is cool Correct answer.
  2. Fill the reservoir to the top every time
  3. Ignore it if the temperature gauge is normal
  4. Remove the radiator cap while the engine is hot

Explanation

Coolant should be checked when the engine is cool to avoid burns from hot pressurized fluid. The level should be between the marked limits.

Question 16Vehicle Inspection and Pre-Trip Procedures

Which drive belt condition requires attention during a pre-trip inspection?

  1. A belt with a smooth surface
  2. A belt that is the correct width
  3. A belt that is snug
  4. A belt that is frayed or glazed Correct answer.

Explanation

Frayed, cracked, or glazed belts can slip or break. They should be replaced before the trip.

Question 17Vehicle Inspection and Pre-Trip Procedures

A driver notices the ABS warning lamp stays on after starting the engine. What does this mean?

  1. The brakes will not work at all
  2. The air pressure is too high
  3. The ABS is not working, but normal brakes may still operate Correct answer.
  4. The trailer is disconnected

Explanation

A steady ABS lamp means the anti-lock function is disabled. The vehicle may still have normal braking, but wheels could lock during a hard stop.

Question 18Vehicle Inspection and Pre-Trip Procedures

When connecting a trailer, the trailer air lines should be:

  1. Left hanging loose
  2. Secured and checked for leaks Correct answer.
  3. Cut and capped
  4. Connected only if the trailer is empty

Explanation

Air lines must be properly connected, supported, and checked for leaks or chafing. Loose lines can rub through or disconnect while driving.

Question 19Vehicle Inspection and Pre-Trip Procedures

What is the purpose of reviewing the previous driver's inspection report?

  1. To identify defects that may need repair before the trip Correct answer.
  2. To learn the fuel mileage
  3. To see if the previous driver was late
  4. To confirm the cargo weight

Explanation

The report tells the next driver about defects found during the previous trip. Those defects must be repaired or noted before the vehicle is used.

Question 20Vehicle Inspection and Pre-Trip Procedures

During an air brake system check, pressure should build from 85 to 100 psi within what time in a dual air system?

  1. 3 minutes
  2. 2 minutes
  3. 45 seconds Correct answer.
  4. 90 seconds

Explanation

A properly working compressor should raise pressure from 85 to 100 psi within 45 seconds in a dual air system. A slower build-up can indicate a compressor or leak problem.

Question 21Vehicle Inspection and Pre-Trip Procedures

What does the tractor protection valve do when the trailer air supply is disconnected?

  1. It keeps air in the tractor and applies the trailer spring brakes Correct answer.
  2. It increases trailer air pressure
  3. It sends all air pressure to the trailer
  4. It prevents the tractor engine from starting

Explanation

The tractor protection valve closes when trailer air pressure is lost or lines separate. This keeps enough air in the tractor for braking and causes the trailer brakes to apply.

Question 22Vehicle Inspection and Pre-Trip Procedures

When checking brake drums, which finding requires the vehicle to be placed out of service?

  1. A visible crack in the drum Correct answer.
  2. A small amount of brake dust
  3. Light surface rust
  4. A factory balance weight

Explanation

A cracked brake drum can fail and cause loss of braking. The vehicle must be taken out of service until the drum is replaced.

Question 23Vehicle Inspection and Pre-Trip Procedures

A driver finds oil leaking from a wheel hub during the walk-around inspection. What is the correct action?

  1. Wipe it off and drive
  2. Identify the leak and have it repaired before driving Correct answer.
  3. Cover the hub with tape
  4. Add oil to the hub

Explanation

A wheel hub oil leak can lead to bearing failure and wheel loss. The leak must be repaired before the vehicle is driven.

Question 24Vehicle Inspection and Pre-Trip Procedures

What should a driver verify about the trailer landing gear before moving the combination vehicle?

  1. That it is lowered halfway
  2. That the crank handle is left hanging loose
  3. That it is fully raised and secured Correct answer.
  4. That it is touching the ground for stability

Explanation

Landing gear must be fully raised before moving, or it can strike the road and cause damage or a crash. The crank handle should also be secured.

Question 25Basic Control, Shifting, and Backing

What should you do first before backing a large vehicle?

  1. Walk around the vehicle to check for obstacles. Correct answer.
  2. Sound the horn twice and back immediately.
  3. Ask a passenger to watch from inside the cab.
  4. Turn on the headlights and use the mirrors.

Explanation

Before backing, walk around the vehicle to check for people, obstacles, and clearance. Mirrors leave blind spots, so a direct look is more reliable. If you have a helper, agree on signals before you start.

Question 26Basic Control, Shifting, and Backing

When backing a heavy vehicle, which gear should you use?

  1. Neutral, letting the vehicle roll.
  2. The highest reverse gear available.
  3. A forward gear with the engine off.
  4. The lowest reverse gear. Correct answer.

Explanation

Backing should be done slowly and smoothly. The lowest reverse gear helps keep speed low so you can stop quickly and steer precisely. Never coast in neutral while backing.

Question 27Basic Control, Shifting, and Backing

You are backing with a helper, and you lose sight of the helper in your mirrors. What should you do?

  1. Stop until you see the helper again. Correct answer.
  2. Open the door and look out while backing.
  3. Continue backing slowly and sound the horn.
  4. Speed up to finish the backing maneuver.

Explanation

If you lose sight of your helper, stop at once; the helper may have moved into a blind spot. Do not resume until you can see the helper again or you have checked the area yourself. A helper's signals are useful only while they remain visible.

Question 28Basic Control, Shifting, and Backing

Where should you focus your eyes when steering a large vehicle down the road?

  1. On the dashboard gauges.
  2. Far ahead in your lane of travel. Correct answer.
  3. On the left mirror only.
  4. On the hood ornament directly in front.

Explanation

Look far ahead in your lane so you can steer smoothly and see hazards early. Aiming high helps you make gradual corrections instead of jerky movements. Checking gauges and mirrors is important, but your main visual lead should be down the road.

Question 29Basic Control, Shifting, and Backing

How should you keep your foot when you are not actively shifting gears?

  1. Off the clutch pedal and on the floor. Correct answer.
  2. Pressing the clutch halfway down.
  3. Resting lightly on the clutch pedal.
  4. Covering the clutch while accelerating.

Explanation

Keep your foot off the clutch when you are not shifting. Resting on the pedal can make the clutch slip, wear it out, and reduce control. Put your foot on the floor and use the clutch only for shifting and stopping.

Question 30Basic Control, Shifting, and Backing

Before shifting an automatic transmission from Drive to Reverse, what must you do?

  1. Apply the parking brake while moving.
  2. Shift through Neutral without stopping.
  3. Rev the engine to match speeds.
  4. Bring the vehicle to a complete stop. Correct answer.

Explanation

Come to a complete stop before moving the selector from Drive to Reverse. Shifting while the vehicle is still rolling can damage the transmission and make the vehicle hard to control. Apply the brake, stop, then select the new range.

Question 31Basic Control, Shifting, and Backing

When should you reduce speed for a curve?

  1. After you are halfway through the curve.
  2. Before you enter the curve. Correct answer.
  3. While accelerating through the curve.
  4. Only if you see a warning sign.

Explanation

Slow down before you enter a curve. Braking hard inside the curve can cause a skid or rollover, especially in a heavy vehicle. Then use gentle acceleration as you come out of the curve.

Question 32Basic Control, Shifting, and Backing

Why is backing toward the driver's side usually safer for a large vehicle?

  1. Traffic laws require backing only to the left.
  2. The driver can see that side better. Correct answer.
  3. The engine has more power in that direction.
  4. The backup alarm is louder on that side.

Explanation

The driver's side usually gives a better view in the left mirror, while the opposite side is the blind side. Backing toward the visible side reduces the chance of hitting something. Use a helper whenever possible, even when backing to the sight side.

Question 33Basic Control, Shifting, and Backing

Where should a helper stand when guiding you while you back?

  1. Directly in front of the vehicle.
  2. Behind the vehicle, visible in a mirror. Correct answer.
  3. Beside the driver's door out of mirror view.
  4. Inside the cab behind the driver.

Explanation

A helper must stand where you can see them in a mirror throughout the maneuver. Agree on hand signals before backing and stop if the helper disappears from view. The helper should never stand directly behind the vehicle where they could be struck.

Question 34Basic Control, Shifting, and Backing

While backing a long vehicle, how should you use your mirrors?

  1. Watch only the left mirror at all times.
  2. Check both mirrors and correct gently. Correct answer.
  3. Use the mirrors only after stopping.
  4. Fold the mirrors in to avoid hitting objects.

Explanation

Check both mirrors repeatedly and correct the steering in small amounts. Large corrections can make the trailer swing too far and lead to a jackknife. Mirrors should be adjusted before you start backing.

Question 35Basic Control, Shifting, and Backing

You are backing and cannot see clearly behind the vehicle even with mirrors. What is the safest action?

  1. Stop and get out to check behind the vehicle. Correct answer.
  2. Rely on the backup alarm to warn others.
  3. Back faster to spend less time in the blind spot.
  4. Ask someone in the cab to guess the distance.

Explanation

Stop and get out to check when your mirrors do not give a clear view. A backup alarm warns others but does not tell you what is behind the vehicle. Backing blindly, even slowly, risks a collision.

Question 36Basic Control, Shifting, and Backing

Before starting down a long downgrade, what should you do?

  1. Use the highest gear possible.
  2. Select a lower gear before descending. Correct answer.
  3. Wait until the vehicle speeds up, then downshift.
  4. Shift to neutral to save fuel.

Explanation

Select a lower gear before the downgrade begins. Engine braking helps control speed and reduces reliance on the brakes. Waiting until the vehicle is already speeding can make downshifting difficult and unsafe.

Question 37Basic Control, Shifting, and Backing

Why should you avoid coasting with the clutch pushed in or in neutral?

  1. You lose engine braking and control. Correct answer.
  2. The steering wheel will lock.
  3. The transmission will shift itself.
  4. The engine will immediately overheat.

Explanation

Coasting with the clutch in or in neutral removes engine braking. That makes the vehicle harder to control, especially on a downgrade. Keep the transmission in gear so engine drag helps manage speed.

Question 38Basic Control, Shifting, and Backing

What is the purpose of double clutching in a non-synchronized manual transmission?

  1. To match engine and gear speeds. Correct answer.
  2. To increase engine speed while parked.
  3. To keep the brakes from overheating.
  4. To bypass the clutch entirely.

Explanation

Double clutching means pressing the clutch, shifting to neutral, releasing the clutch, pressing it again, and then selecting the next gear. This helps match engine and transmission speeds in a non-synchronized transmission. It is not needed in an automatic or synchronized manual.

Question 39Basic Control, Shifting, and Backing

Which steering method is recommended for a large vehicle?

  1. Fingertips only at the top of the wheel.
  2. Palming the wheel with the palm.
  3. Both hands, hand-over-hand for turns. Correct answer.
  4. One hand at the bottom of the wheel.

Explanation

Use both hands on the wheel and hand-over-hand steering for turns. This gives better control than palming or using fingertips. Keep your grip firm but relaxed so you can react quickly.

Question 40Basic Control, Shifting, and Backing

When backing a tractor-trailer in a straight line, what should you do?

  1. Make small corrections and check both mirrors. Correct answer.
  2. Accelerate hard to keep the trailer straight.
  3. Keep the steering wheel turned slightly at all times.
  4. Make large steering corrections quickly.

Explanation

Make small steering corrections and watch both mirrors as you back. Oversteering can make the trailer swing too far and start a jackknife. If the rig gets out of line, stop and pull forward to straighten it.

Question 41Basic Control, Shifting, and Backing

How can you prevent rolling backward when starting on a hill?

  1. Use the parking brake until the engine begins to pull. Correct answer.
  2. Release the clutch quickly before accelerating.
  3. Put the transmission in neutral.
  4. Press the accelerator before releasing the parking brake.

Explanation

Use the parking brake to hold the vehicle while you let the clutch engage. Release the brake smoothly as the engine begins to pull. This prevents rolling backward into a vehicle or object behind you.

Question 42Basic Control, Shifting, and Backing

About how far ahead should you look when driving at highway speeds?

  1. Only as far as the vehicle in front.
  2. Thirty to forty-five seconds.
  3. One to two seconds.
  4. Twelve to fifteen seconds. Correct answer.

Explanation

Look about twelve to fifteen seconds ahead at highway speeds. That gives you time to spot hazards and adjust smoothly. At lower speeds, the distance is shorter, but you should still aim well ahead.

Question 43Basic Control, Shifting, and Backing

After starting a heavy vehicle's engine, what should you do before moving?

  1. Rev the engine several times.
  2. Turn off the engine and restart it.
  3. Check that gauges show normal readings. Correct answer.
  4. Release the parking brake and accelerate.

Explanation

After starting the engine, check the gauges and warning lights. Make sure oil pressure is normal and air pressure is building before you move. Release the parking brake only after the vehicle is ready.

Question 44Basic Control, Shifting, and Backing

You are backing a tractor-trailer and want the rear of the trailer to move to your left. Which way should you turn the steering wheel?

  1. It does not matter while backing.
  2. Right. Correct answer.
  3. Straight ahead while accelerating.
  4. Left.

Explanation

For a tractor-trailer, steer opposite the direction you want the trailer rear to go. Turning the wheel right moves the trailer rear to the left. Then make small follow-up corrections to keep the trailer on line.

Question 45Basic Control, Shifting, and Backing

While backing a tractor-trailer, the trailer starts to turn too sharply and the rig begins to jackknife. What should you do?

  1. Accelerate to push the trailer straight.
  2. Continue backing and steer harder into the turn.
  3. Apply the trailer brakes only and keep backing.
  4. Stop and pull forward to straighten the rig. Correct answer.

Explanation

Stop and pull forward to reduce the angle between the tractor and trailer. Continuing to back while the angle grows can cause a jackknife or damage. Straighten the rig before trying again.

Question 46Basic Control, Shifting, and Backing

Why must you swing wide when turning a long vehicle?

  1. To increase engine power in the turn.
  2. To keep the trailer brakes cool.
  3. Because the rear wheels follow a shorter path. Correct answer.
  4. Because the steering wheel turns farther than in a car.

Explanation

The rear wheels of a long vehicle follow a shorter path than the front wheels, which is called off-tracking. Swinging wide gives the rear wheels room to clear the corner. Without it, the trailer or rear tires can strike the curb or nearby objects.

Question 47Basic Control, Shifting, and Backing

How should you use the brakes on a long downgrade to help prevent overheating?

  1. Apply the parking brake partially.
  2. Use the brakes only after the vehicle is speeding.
  3. Brake firmly to slow, then release and repeat. Correct answer.
  4. Keep light constant pressure on the brake pedal.

Explanation

Use firm braking to reduce speed, then release the brakes and repeat as needed. This snub braking lets the brakes cool between applications. Light constant pressure can overheat the brakes and cause fade.

Question 48Basic Control, Shifting, and Backing

When making a tight turn in a long vehicle, what hazard does the rear overhang create?

  1. The trailer brakes may release automatically.
  2. The rear may swing out and hit objects. Correct answer.
  3. The steering wheel may become harder to turn.
  4. The front wheels may lose traction.

Explanation

The rear overhang can swing outward as the front of the vehicle turns. This swing can strike poles, signs, or other vehicles near the corner. Check clearance and allow extra room before starting the turn.

Question 49Seeing and Communicating

At highway speed, how far ahead should you scan the road so you have time to spot hazards and react?

  1. Twelve to fifteen seconds ahead Correct answer.
  2. One to two seconds ahead
  3. Twenty-five to thirty seconds ahead
  4. Four to six seconds ahead

Explanation

At highway speed a vehicle covers a long distance in only a few seconds, so searching 12 to 15 seconds ahead gives you time to spot hazards, plan a lane change, and react smoothly. Looking only a couple of seconds ahead leaves no room to stop or steer around a problem that suddenly appears.

Question 50Seeing and Communicating

Just before you move your vehicle into an adjacent lane, what is the final check for a vehicle hidden in your blind spot?

  1. A check of the flat mirror on your door
  2. A hand signal to the drivers behind you
  3. A look in the convex mirror on the passenger side
  4. A quick glance over your shoulder Correct answer.

Explanation

Mirrors do not show the area directly beside and slightly behind the cab, so a quick head turn is the only way to confirm that the space is clear before moving over. Signal first, check the mirrors, then glance over the shoulder and change lanes only when the lane is open.