CDL Commercial Learner's Permit (CLP) Exam — Questions and Answers

Question 1: Which of the following best describes why a pre-trip inspection is required by federal law?

To satisfy insurance requirements for commercial vehicles
To document vehicle mileage for fleet management
To ensure the vehicle is safe to operate and identify defects before driving (Correct answer)
To verify the driver's license is current before each trip

Correct answer: To ensure the vehicle is safe to operate and identify defects before driving

FMCSA regulations require pre-trip inspections to identify vehicle defects that could cause accidents or breakdowns before the vehicle is placed in service.

Question 2: Before using tire chains in winter conditions, you should inspect them for what?

Sidewall pressure ratings
Color coding and manufacturer markings
Tread depth rating compatibility
Proper fit and missing or broken cross links (Correct answer)

Correct answer: Proper fit and missing or broken cross links

Chains must be inspected for proper fit and any missing or damaged cross links before use, as broken chains can damage the vehicle.

Question 3: During a CDL pre-trip inspection, which component is checked to ensure the vehicle's steering is safe?

Steering wheel free play and steering gear box for leaks and secure mounting (Correct answer)
Condition of the windshield wiper fluid reservoir
Alignment of the front axle using a laser measurement tool
Horsepower output of the power steering pump

Correct answer: Steering wheel free play and steering gear box for leaks and secure mounting

Inspectors check for excessive steering wheel play (more than 10 degrees on a 20-inch wheel) and inspect the steering gear box for leaks and secure mounting.

Question 4: What happens to a CLP if the holder's regular driver's license is suspended?

The CLP remains valid and can still be used to drive CMVs
The CLP is also invalidated and cannot be used (Correct answer)
The CLP can be used for intrastate driving only
The CLP is automatically downgraded to a Class C

Correct answer: The CLP is also invalidated and cannot be used

A CLP is tied to the validity of the underlying driver's license — a suspension of the base license also invalidates the CLP.

Question 5: In which of the following situations is a commercial motor vehicle driver ALWAYS required by federal law to stop at a railroad-highway grade crossing?

When the vehicle is transporting placarded hazardous materials. (Correct answer)
When driving any vehicle with dual rear axles, regardless of cargo.
When approaching any crossing that does not have active warning signals like lights or gates.
When the driver is hauling empty cargo tanks that will be used to transport hazardous materials.

Correct answer: When the vehicle is transporting placarded hazardous materials.

FMCSA regulation §392.10 requires all CMVs carrying placarded hazardous materials to stop at all railroad crossings. This rule also applies to passenger buses and certain other specific vehicles. The other situations do not impose a mandatory stop unless a train is approaching or signals are active.

Question 6: What hazard does a cracked or broken brake drum present during a pre-trip inspection?

Brake failure due to structural collapse under heat and pressure (Correct answer)
Reduced fuel efficiency
Lower air pressure consumption
Increased brake pedal travel

Correct answer: Brake failure due to structural collapse under heat and pressure

A cracked brake drum can fail catastrophically under the heat and mechanical stress of braking, causing complete brake failure on that wheel.

Question 7: Which scenario allows a CLP holder to legally operate a tank vehicle for practice?

Tank vehicle practice is prohibited for all CLP holders
Any CLP holder may practice in a tank vehicle with supervision
Only if the CLP includes the tank vehicle (N) endorsement and the holder is supervised (Correct answer)
Only if the vehicle is empty and parked on private property

Correct answer: Only if the CLP includes the tank vehicle (N) endorsement and the holder is supervised

To practice operating a tank vehicle, the CLP must include the N (tank vehicle) endorsement, and the holder must be supervised by a qualified CDL holder.

Question 8: Under the CDL Drug and Alcohol Clearinghouse rules, employers must query the clearinghouse before hiring a CDL driver:

For every pre-employment hire (Correct answer)
Only if the driver was previously disqualified
Only for drivers who will transport hazardous materials
Only for interstate drivers

Correct answer: For every pre-employment hire

Employers must conduct a pre-employment full query of the Drug and Alcohol Clearinghouse for every prospective CDL driver hire.

Question 9: What is the 'escape ramp' or 'runaway truck ramp' designed to do?

Stop a CMV whose brakes have failed on a downgrade (Correct answer)
Allow trucks to bypass weigh stations
Provide a rest area for tired drivers on steep grades
Redirect trucks that have taken a wrong turn

Correct answer: Stop a CMV whose brakes have failed on a downgrade

Escape ramps use deep gravel or sand and an uphill slope to safely decelerate and stop a runaway truck with brake failure.

Question 10: What effect does cold weather have on air brake systems, and how should drivers prepare?

Cold weather reduces compressor output — drivers need more warm-up time before driving
Brake drums contract in cold weather, making adjustment unnecessary until temperatures rise
Cold air is denser, increasing pressure — drivers should reduce pressure by 10 psi in winter
Moisture in the system can freeze, blocking valves and lines — drivers should drain tanks and use alcohol evaporators or air dryers (Correct answer)

Correct answer: Moisture in the system can freeze, blocking valves and lines — drivers should drain tanks and use alcohol evaporators or air dryers

Moisture that collects in air tanks and lines can freeze in cold weather, blocking air flow — draining tanks daily and ensuring the air dryer works properly prevents this.

Question 11: What is the maximum legal weight on a single steering axle for most US highways?

80,000 pounds
12,000 pounds
20,000 pounds (Correct answer)
34,000 pounds

Correct answer: 20,000 pounds

Federal regulations set the maximum weight on a single steering axle at 20,000 pounds on the Interstate highway system.

Question 12: When should you downshift a manual transmission commercial vehicle?

Only after reaching the bottom of a hill
Before entering a curve or grade, not while in it (Correct answer)
Whenever the engine reaches maximum RPM
While braking to make the stop shorter

Correct answer: Before entering a curve or grade, not while in it

Downshift before curves and hills so you can focus on steering and speed control rather than shifting during the maneuver.

Question 13: Which of the following best describes a hazardous material placard?

A written permit attached to the cab
A diamond-shaped sign displayed on the vehicle identifying the hazard class (Correct answer)
A document carried by the driver listing all cargo
A color-coded stripe on the trailer

Correct answer: A diamond-shaped sign displayed on the vehicle identifying the hazard class

Placards are diamond-shaped warning signs mounted on the outside of vehicles to identify the hazard class of the materials being transported.

Question 14: What is the danger of 'over-braking' on a slippery surface?

It can cause wheels to lock up, leading to loss of steering control (Correct answer)
It engages the jake brake unintentionally
It increases air pressure in the system
It causes brake overheating on any surface

Correct answer: It can cause wheels to lock up, leading to loss of steering control

Applying brakes too hard on slippery pavement can lock the wheels, causing the vehicle to slide straight regardless of steering input.

Question 15: What is the maximum length of a safety chain or cable used to secure a converter dolly to the lead trailer?

Long enough to prevent the dolly from swinging wide but short enough to keep it under the trailer if the pintle hook fails (Correct answer)
As long as needed to reach the rear of the lead trailer
Exactly 10 feet regardless of trailer length
Safety chains are not required on converter dollies

Correct answer: Long enough to prevent the dolly from swinging wide but short enough to keep it under the trailer if the pintle hook fails

Safety chains must be short enough to prevent the dolly from touching the ground if it separates, limiting swing and ground contact.

Question 16: Why is it important to check the header board on a flatbed trailer during a pre-trip inspection?

It connects to the fifth wheel safety mechanism
It controls trailer lighting circuits
It prevents cargo from sliding forward into the cab during hard braking (Correct answer)
It is required for weight distribution certification

Correct answer: It prevents cargo from sliding forward into the cab during hard braking

The header board (headache rack) protects the cab from cargo shifting forward under hard braking or in a collision.

Question 17: When chains are required for a commercial vehicle, which axles are typically required to be chained?

All drive axles (Correct answer)
Only the steering axle
Only the trailer axles
All axles including trailer

Correct answer: All drive axles

Chain requirements for commercial vehicles typically mandate chains on all drive axles to ensure traction.

Question 18: What is the primary reason for conducting a post-trip inspection?

To satisfy FMCSA paperwork requirements only
To identify defects that could affect safety of the next trip and document them for repair (Correct answer)
To confirm cargo weight before unloading
To calculate fuel usage for the trip

Correct answer: To identify defects that could affect safety of the next trip and document them for repair

A post-trip inspection helps find defects that developed during the trip so they can be repaired before the vehicle is used again.

Question 19: What action should a driver take before driving under a low bridge or overpass with an oversized load?

Verify the actual clearance against the load's height and obtain any required permits (Correct answer)
Sound the horn and proceed slowly
Drive in the center of the road for maximum clearance
Reduce tire pressure to lower the vehicle height

Correct answer: Verify the actual clearance against the load's height and obtain any required permits

Before proceeding under any structure with an oversized load, the driver must verify the posted clearance exceeds the load height and carry any required oversize permits.

Question 20: How much air pressure loss per minute is acceptable for a combination vehicle during the static leakage test with brakes released?

1 psi or less
3 psi or less
5 psi or less (Correct answer)
8 psi or less

Correct answer: 5 psi or less

For a combination vehicle with brakes released, the air pressure should not drop more than 4 psi in one minute (3 psi for single vehicles); 5 psi or less is acceptable.

Question 21: For how long must a carrier retain a driver's records of duty status under federal regulations?

12 months
3 months
3 years
6 months (Correct answer)

Correct answer: 6 months

Federal regulations require carriers to retain driver records of duty status for a minimum of 6 months.

Question 22: Which endorsement is required to transport hazardous materials requiring placards?

N endorsement
T endorsement
X endorsement
H endorsement (Correct answer)

Correct answer: H endorsement

The H endorsement authorizes a CDL holder to transport hazardous materials that require placarding under federal regulations.

Question 23: How far should the landing gear be cranked down when uncoupling a trailer on a firm, level surface?

Until the landing gear fully extends to its maximum length
Landing gear position does not matter if the kingpin is locked
Only a few turns just to stabilize the trailer
Until it just contacts the ground and the weight is transferred off the fifth wheel (Correct answer)

Correct answer: Until it just contacts the ground and the weight is transferred off the fifth wheel

The landing gear should bear the trailer's weight before uncoupling so the trailer is stable and the fifth wheel can be released safely.

Question 24: How does a CLP restriction for a manual transmission affect the CDL skills test?

The restriction has no effect on the skills test vehicle choice
The CLP holder can still take the skills test in a manual transmission vehicle (Correct answer)
The restriction is automatically removed before the skills test
The CLP holder must take the skills test in an automatic transmission vehicle

Correct answer: The CLP holder can still take the skills test in a manual transmission vehicle

A manual transmission restriction on a CLP limits practice vehicles, but the CLP holder can still take the skills test in a manual vehicle to earn a CDL without that restriction.

Question 25: Hydroplaning in a commercial vehicle is most likely to occur when?

Making a wide right turn
Braking lightly on dry pavement
Driving uphill at low speeds
Driving at high speed over standing water (Correct answer)

Correct answer: Driving at high speed over standing water

Hydroplaning occurs when tires lose contact with the road surface due to water buildup, and is most likely at higher speeds over standing water.

Question 26: A CLP applicant taking the Combination Vehicles knowledge test should expect questions about which topic?

Hours of service regulations specific to team drivers
Weight distribution on single-unit straight trucks
Coupling systems, rollover prevention, and handling doubles or triples (Correct answer)
Loading refrigerated trailers for perishable goods

Correct answer: Coupling systems, rollover prevention, and handling doubles or triples

The Combination Vehicles test covers tractor-trailer coupling, trailer sway, safe handling, and multiple trailer operations.

Question 27: When approaching a sharp curve or an exit ramp, what is the correct speed management technique for a commercial vehicle?

Accelerate before the curve and coast through it.
Maintain your highway speed until you are in the middle of the curve.
Brake firmly throughout the entire curve.
Slow down to a safe speed before entering the curve. (Correct answer)

Correct answer: Slow down to a safe speed before entering the curve.

Due to their high center of gravity, commercial vehicles are prone to rollovers on curves. The correct and safest technique is to reduce speed *before* entering the curve and then maintain that safe speed throughout. Braking in a curve can cause a loss of traction and lead to a skid or rollover.

Question 28: What is the purpose of the tractor protection valve?

To prevent the driver from applying trailer brakes without applying tractor brakes first
To lock the fifth wheel automatically if trailer air pressure drops
To regulate the pressure difference between primary and secondary air systems
To protect the tractor's air supply if the trailer develops a large air leak or breaks away (Correct answer)

Correct answer: To protect the tractor's air supply if the trailer develops a large air leak or breaks away

The tractor protection valve closes automatically if trailer air pressure drops too low, preserving the tractor's air supply so the tractor brakes continue to function.

Question 29: A driver transporting hazardous materials must have a hazardous materials endorsement on their CDL. What does this endorsement require the driver to pass?

An OSHA certification course
A Transportation Security Administration (TSA) background check and a written knowledge test (Correct answer)
A road skills test in a hazmat vehicle
Only a physical examination

Correct answer: A Transportation Security Administration (TSA) background check and a written knowledge test

The HazMat endorsement requires both a TSA security threat assessment (background check) and passing the state's hazardous materials knowledge test.

Question 30: When inspecting the coupling system on a combination vehicle, what does it mean if you can insert the fifth wheel safety latch (lock handle) while the kingpin is engaged?

This is normal and expected
The coupling is properly locked
The latch is defective and the vehicle should not be driven (Correct answer)
The kingpin is oversized

Correct answer: The latch is defective and the vehicle should not be driven

If the safety latch can be inserted after coupling, the locking mechanism is defective and the trailer could separate from the tractor.

Question 31: What is the primary, approved use of the trailer hand valve (also known as the trolley valve or Johnson bar)?

For regular parking instead of the spring brakes.
To test the trailer service brakes. (Correct answer)
To prevent the vehicle from rolling back on a hill.
To assist with making tight turns.

Correct answer: To test the trailer service brakes.

The trailer hand valve should only be used to test the application of the trailer's service brakes to ensure they are working correctly. It should not be used for parking, as air could leak out, or for braking during driving, as it can cause the trailer wheels to lock up and skid.

Question 32: When inspecting air brake hoses and lines during a pre-trip inspection, what conditions should cause you to take the vehicle out of service?

Hoses that are cracked, chafed, worn through, crimped, or leaking air (Correct answer)
Lines that are routed within 6 inches of the exhaust system
Hoses that show slight discoloration from engine heat exposure
Hoses that have any color other than black

Correct answer: Hoses that are cracked, chafed, worn through, crimped, or leaking air

Air brake hoses with cracks, chafing, visible wear, crimps, or active air leaks must be repaired before the vehicle is operated, as these indicate potential failure.

Question 33: Under the FMCSA rules, what is a 'short-haul exemption' from keeping a logbook?

Drivers with fewer than 2 years of CDL experience are exempt for training purposes
Drivers who operate only on private property never need a logbook
Drivers who stay within 150 air-miles of their home terminal and return within 14 hours may use time records instead of logs (Correct answer)
Drivers who carry only non-hazardous materials are exempt from all HOS rules

Correct answer: Drivers who stay within 150 air-miles of their home terminal and return within 14 hours may use time records instead of logs

The short-haul exemption allows eligible drivers within 150 air miles who return to the home terminal within 14 hours to use time records rather than full RODS.

Question 34: During a training session, the CLP holder's supervisor falls asleep in the passenger seat. What should the CLP holder do?

Continue driving carefully since a CDL holder is physically present in the vehicle
Reduce speed and complete only the remaining portion of the planned route
Safely pull the vehicle off the road and wake the supervisor before continuing (Correct answer)
Drive to the nearest rest stop and wait for another qualified supervisor to arrive

Correct answer: Safely pull the vehicle off the road and wake the supervisor before continuing

Supervision requires the CDL holder to be alert and able to intervene; an asleep supervisor does not fulfill the legal supervision requirement.

Question 35: When transporting hazardous materials, a driver should use routes that avoid populated areas whenever possible. This is required primarily for which reason?

To limit the risk of harm to the public in case of a spill or accident (Correct answer)
Because hazmat vehicles are prohibited from driving in cities
To reduce fuel costs by avoiding traffic
To comply with weight restrictions in urban areas

Correct answer: To limit the risk of harm to the public in case of a spill or accident

Routing hazmat vehicles away from populated areas minimizes the number of people at risk if a spill, fire, or explosion occurs during transport.

Question 36: A driver notices the truck is pulling to one side during braking. What is the most likely cause?

Uneven brake adjustment or a dragging brake on one side (Correct answer)
The load is centered too far forward
Air pressure is too high in the brake system
The steering wheel is not centered during the stop

Correct answer: Uneven brake adjustment or a dragging brake on one side

Uneven braking force — caused by misadjusted or dragging brakes — pulls the vehicle toward the side with greater stopping force.

Question 37: What action should you take if your vehicle becomes stuck on a railroad crossing with a train approaching?

Stay in the vehicle and sound the horn to warn the train
Stay in the vehicle with your seatbelt on and wait for help
Try to rock the vehicle free by shifting between forward and reverse
Abandon the vehicle and run away from the tracks at an angle in the direction the train is coming from (Correct answer)

Correct answer: Abandon the vehicle and run away from the tracks at an angle in the direction the train is coming from

You should immediately get out and run away from the tracks at an angle toward the oncoming train to avoid debris that could fly in the train's direction of travel.

Question 38: The total stopping distance for a commercial motor vehicle is comprised of three distinct parts. Which of the following correctly lists these three parts?

Perception distance, reaction distance, and braking distance (Correct answer)
Alertness distance, engagement distance, and stopping distance
Following distance, braking distance, and reaction distance
Visual distance, mechanical distance, and friction distance

Correct answer: Perception distance, reaction distance, and braking distance

Total stopping distance is the sum of the distance your vehicle travels from the time you see a hazard until you come to a complete stop. This process is broken down into three stages: Perception distance (seeing the hazard), Reaction distance (moving your foot to the brake), and Braking distance (the distance the vehicle travels after the brakes are applied).

Question 39: A driver is transporting steel coils on a flatbed. What special securement method is typically required for coils positioned with their eyes vertical?

Coils must always be transported in closed trailers
Chocks or wedges plus straps must be used to prevent rolling (Correct answer)
Only standard straps are needed
The coils must be welded to the trailer deck

Correct answer: Chocks or wedges plus straps must be used to prevent rolling

Steel coils with eyes vertical must be secured with chocks, wedges, or cradles to prevent rolling, in addition to tie-down straps, due to their cylindrical shape.

Question 40: On a paper log, duty status changes must be recorded to the nearest increment of how many minutes?

30 minutes
15 minutes (Correct answer)
10 minutes
5 minutes

Correct answer: 15 minutes

Paper logs must record all duty status changes to the nearest 15-minute (quarter-hour) increment on the graph grid.

Question 41: Which of the following scenarios would be an illegal supervised driving situation under federal CLP rules?

A CLP holder driving a tanker with a supervisor who holds a Class A CDL without a tanker endorsement sitting in the passenger seat (Correct answer)
A CLP holder driving a straight truck with a supervisor who holds a Class B CDL in the passenger seat
A CLP holder driving a school bus with no students and a supervisor with a Class B CDL and S endorsement in the passenger seat
A CLP holder driving a tanker with a supervisor who holds a Class A CDL with a tanker endorsement in the passenger seat

Correct answer: A CLP holder driving a tanker with a supervisor who holds a Class A CDL without a tanker endorsement sitting in the passenger seat

When a CLP holder has a tanker (N) endorsement, the accompanying CDL holder must also hold the tanker endorsement on their license.

Question 42: What should a CDL driver do if the steering feels unusually heavy or unresponsive while driving?

Increase speed to generate more turning force
Continue driving and report the issue after completing the delivery
Apply brakes immediately and stop in the travel lane
Pull off safely and inspect for a flat tire or steering system problem (Correct answer)

Correct answer: Pull off safely and inspect for a flat tire or steering system problem

Heavy or unresponsive steering often indicates a flat tire, low power steering fluid, or a mechanical failure that must be inspected immediately.

Question 43: Which activity is classified as off-duty time and does NOT count toward a driver's on-duty hours?

Sleeping in a sleeper berth (Correct answer)
Performing a vehicle inspection
Waiting at a shipper
Loading cargo

Correct answer: Sleeping in a sleeper berth

Time spent resting in a sleeper berth is classified as off-duty and does not count toward on-duty hours.

Question 44: Which of the following actions requires a CDL driver to notify their employer within 30 days?

Changing their home address
Receiving any traffic conviction in any vehicle (Correct answer)
Purchasing a new personal vehicle
Completing a defensive driving course

Correct answer: Receiving any traffic conviction in any vehicle

CDL drivers must notify their employer within 30 days of any traffic conviction, regardless of what vehicle they were driving.

Question 45: What is the off-tracking difference in a long combination vehicle compared to a single unit truck?

Off-tracking only occurs in reverse, not in forward turns
The rear wheels follow a significantly shorter path (inside) than the front wheels when turning (Correct answer)
All axles follow exactly the same path in a combination vehicle
The rear wheels follow a longer path (outside) than the front wheels

Correct answer: The rear wheels follow a significantly shorter path (inside) than the front wheels when turning

Off-tracking causes the rear wheels to cut corners more severely than the front wheels, requiring drivers to allow extra space on the inside of turns.

Question 46: When preparing to back a commercial vehicle, what is the MOST important first step a driver should take?

Get out of the vehicle and walk around it to check for hazards. (Correct answer)
Ask a bystander to act as a spotter.
Turn on the hazard lights and sound the horn.
Immediately begin backing slowly while checking mirrors.

Correct answer: Get out of the vehicle and walk around it to check for hazards.

The most critical first step before backing is to perform a walk-around inspection of the area. This practice, often called G.O.A.L. (Get Out And Look), allows the driver to identify any obstacles, overhead clearances, ground conditions, or people that may not be visible in the mirrors.

Question 47: Which trailer should be placed immediately behind the tractor in a double trailer combination?

Either trailer; order does not affect safety
The lighter trailer, to reduce tongue weight on the fifth wheel
The heavier trailer, to improve stability and reduce rearward amplification (Correct answer)
The longest trailer, regardless of weight

Correct answer: The heavier trailer, to improve stability and reduce rearward amplification

Placing the heavier trailer closest to the tractor reduces rearward amplification and improves overall stability of the combination.

Question 48: In a team driving operation, how must the co-driver's name be recorded?

On both drivers' daily logs (Correct answer)
Only on the lead driver's log
Only on the shipping manifest
Only on the vehicle inspection report

Correct answer: On both drivers' daily logs

In team operations, each driver must list the co-driver's name on their own daily log.

Question 49: What is the primary reason for using edge protectors when securing cargo with straps?

To prevent straps from being cut by sharp cargo edges, maintaining their rated strength (Correct answer)
To make loading faster by reducing friction
To add extra weight to the anchor points
To color-code different types of loads for identification

Correct answer: To prevent straps from being cut by sharp cargo edges, maintaining their rated strength

Edge protectors prevent tie-down straps from being cut or weakened by sharp cargo edges, ensuring the strap maintains its full working load limit throughout the trip.

Question 50: What self-certification category must an interstate CLP applicant choose?

Non-excepted interstate (NI) (Correct answer)
Excepted interstate (EI)
Non-excepted intrastate (NI)
Excepted intrastate (EI)

Correct answer: Non-excepted interstate (NI)

An interstate driver who is not exempt from FMCSA regulations must self-certify as 'Non-excepted interstate,' which requires a current medical examiner's certificate on file with their state.

Question 51: What does the yellow diamond-shaped control in the cab control?

The tractor parking and spring brakes (Correct answer)
The engine compression brake (jake brake)
The air dryer heating element in winter
The trailer air supply and emergency brakes

Correct answer: The tractor parking and spring brakes

The yellow diamond-shaped control is the trailer air supply valve, which when pulled out shuts off air to the trailer and applies the trailer emergency brakes.

CDL Commercial Learner's Permit (CLP) Exam

The Commercial Learner's Permit (CLP) knowledge exam is administered by each state's Department of Motor Vehicles and is required before obtaining a Commercial Driver's License (CDL). It is based on the Federal Motor Carrier Safety Administration (FMCSA) CDL standards. The exam covers general knowledge, air brakes, combination vehicles, pre-trip inspection, cargo handling, hours of service, and adverse driving conditions. Passing score is typically 80%. Applicants must pass the relevant sections for their desired CDL class and endorsements.

Questions

90 min

Time Limit

80%

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