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ND CDL General Knowledge study materials
ND CDL General Knowledge study resources

ND CDL General Knowledge practice questions

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Question 1General Knowledge (CDL Manual core section)

Under ND CDL general knowledge rules, what is the maximum number of hours a driver may drive after having been on duty for 15 consecutive hours?

  1. 11 hours Correct answer.
  2. 8 hours
  3. 10 hours
  4. 12 hours

Explanation

The 15-hour on-duty window allows a maximum of 11 hours of driving within it. Once the driver reaches 11 driving hours, no further driving is permitted until a qualifying off-duty period resets the window.

Question 2General Knowledge (CDL Manual core section)

A driver operating under the 60-hour/7-day rule must stop driving when the accumulated on-duty time reaches how many hours in seven consecutive days?

  1. 80 hours
  2. 70 hours
  3. 60 hours Correct answer.
  4. 50 hours

Explanation

The 60-hour/7-day option caps on-duty time at 60 hours within seven consecutive days. The alternative 70-hour/8-day option applies only when the carrier uses that cycle.

Question 3General Knowledge (CDL Manual core section)

What is the minimum number of consecutive off-duty hours required to reset the 11-hour driving and 15-hour on-duty limits?

  1. 10 consecutive hours Correct answer.
  2. 8 consecutive hours
  3. 12 consecutive hours
  4. 6 consecutive hours

Explanation

Ten consecutive off-duty hours reset the daily driving and on-duty clocks. Shorter breaks do not restart those limits.

Question 4General Knowledge (CDL Manual core section)

After a vehicle inspection reveals a brake defect that makes the vehicle unsafe, what must the driver do before operating it?

  1. Repair the defect or have it repaired before driving Correct answer.
  2. Drive it only on secondary roads
  3. Reduce speed by 10 mph and continue
  4. Report the defect at the next scheduled maintenance

Explanation

A vehicle with a defect affecting safe operation must be repaired before it is driven. Continuing with a known unsafe condition violates the out-of-service concept and endangers others.

Question 5General Knowledge (CDL Manual core section)

During a pre-trip inspection, which item should be checked for proper free play?

  1. Fuel cap
  2. Cargo tarp
  3. Sun visor
  4. Steering wheel Correct answer.

Explanation

Excessive steering wheel free play indicates worn steering components and is a safety defect. The pre-trip inspection specifically calls for checking steering play.

Question 6General Knowledge (CDL Manual core section)

In a vehicle equipped with air brakes, what does a rapid loss of air pressure during a static leak test most likely indicate?

  1. A full air tank
  2. Normal compressor cycling
  3. Proper slack adjuster function
  4. A leak in the air system Correct answer.

Explanation

Air pressure should hold steady when the system is static; a rapid drop signals a leak. Leaks must be found and repaired before the vehicle is placed in service.

Question 7General Knowledge (CDL Manual core section)

What is the purpose of a front-wheel limiting valve on some air-brake systems?

  1. Lock the front wheels during hard stops
  2. Reduce front braking force to help maintain steering control Correct answer.
  3. Increase rear braking force
  4. Disable the parking brake

Explanation

A front-wheel limiting valve reduces front brake application pressure under certain conditions to help retain steering control. It is not intended to increase braking or lock wheels.

Question 8General Knowledge (CDL Manual core section)

When should a driver use the parking brake on a commercial vehicle?

  1. Only when parked on a hill
  2. Only when carrying hazardous materials
  3. Whenever the vehicle is parked Correct answer.
  4. Only when the engine is off

Explanation

The parking brake should be set whenever the vehicle is parked to prevent movement. Relying on gear selection alone is not sufficient.

Question 9General Knowledge (CDL Manual core section)

A driver approaching a downgrade with a heavy load should select a gear that:

  1. Allows the vehicle to coast freely
  2. Engages only after the brakes begin to fade
  3. Matches the speed the driver can safely descend without overheating brakes Correct answer.
  4. Provides the highest possible speed

Explanation

The correct gear on a downgrade is one that keeps speed controlled without excessive brake use. Coasting or relying on brakes alone can lead to brake fade.

Question 10General Knowledge (CDL Manual core section)

What is the safest action when a driver's vehicle begins to hydroplane on a wet road?

  1. Release the accelerator and avoid hard braking Correct answer.
  2. Turn sharply to the shoulder
  3. Apply the brakes firmly
  4. Accelerate to regain traction

Explanation

Hydroplaning is best handled by easing off the accelerator and avoiding sudden braking or steering so the tires can regain contact with the road. Hard inputs can cause a loss of control.

Question 11General Knowledge (CDL Manual core section)

When driving in fog, which lighting practice is recommended for a commercial vehicle?

  1. Use low beams and reduce speed Correct answer.
  2. Use high beams for maximum visibility
  3. Use only parking lights
  4. Turn on hazard lights and maintain speed

Explanation

Low beams reduce glare reflected by fog and should be paired with reduced speed. High beams worsen visibility by reflecting light back at the driver.

Question 12General Knowledge (CDL Manual core section)

What is the proper way to check clearance before driving under a low bridge or overpass?

  1. Assume standard clearance is sufficient
  2. Check the posted clearance sign against the vehicle's height Correct answer.
  3. Estimate height by eye
  4. Ask a passenger to watch from the cab

Explanation

Posted clearance signs provide the reliable measurement, and the driver must know the vehicle's total height including cargo. Visual estimation is unreliable and can lead to a bridge strike.

Question 13General Knowledge (CDL Manual core section)

When backing a tractor-trailer, which technique helps maintain control?

  1. Back quickly to reduce time in the blind spot
  2. Rely solely on the backup alarm
  3. Turn the wheel opposite the desired trailer direction
  4. Use the mirrors and back slowly, checking both sides Correct answer.

Explanation

Slow backing with continuous mirror checks keeps the trailer visible and controllable. Speed reduces reaction time and increases the risk of jackknifing.

Question 14General Knowledge (CDL Manual core section)

What action should a driver take if a tire blows out at highway speed?

  1. Brake hard immediately
  2. Accelerate to stabilize the vehicle
  3. Hold the steering wheel firmly and slow gradually Correct answer.
  4. Steer sharply onto the shoulder

Explanation

A firm grip on the wheel and gradual deceleration allow the driver to maintain control after a blowout. Hard braking or sharp steering can cause a loss of control.

Question 15General Knowledge (CDL Manual core section)

At what blood alcohol concentration is a commercial driver considered under the influence under federal rules?

  1. 0.08
  2. 0.04 Correct answer.
  3. 0.02
  4. 0.10

Explanation

Commercial drivers are held to a stricter standard of 0.04 blood alcohol concentration. This is lower than the 0.08 threshold commonly applied to non-commercial drivers.

Question 16General Knowledge (CDL Manual core section)

A driver is convicted of a first offense of driving a CMV with a blood alcohol concentration of 0.04 or higher. What is the required consequence?

  1. A fine with no disqualification
  2. A warning letter only
  3. Loss of CMV driving privileges for one year Correct answer.
  4. A 30-day suspension

Explanation

A first conviction for operating a CMV while under the influence results in a one-year disqualification. A second offense results in lifetime disqualification.

Question 17General Knowledge (CDL Manual core section)

What is the purpose of the driver vehicle inspection report (DVIR) required for certain commercial vehicles?

  1. To record fuel purchases
  2. To schedule deliveries
  3. To document defects found during inspection and certify repairs Correct answer.
  4. To log hours of service

Explanation

The DVIR records any defects discovered during inspection and documents that required repairs were made. It supports the safety inspection process rather than administrative or fuel tracking.

Question 18General Knowledge (CDL Manual core section)

When securing cargo, what does the working load limit of tiedown assemblies refer to?

  1. The maximum load the assembly is designed to support in service Correct answer.
  2. The total weight of the vehicle
  3. The weight of the cargo only
  4. The maximum weight the assembly can carry

Explanation

Working load limit is the maximum load a tiedown assembly is designed to support in normal service. It is used to determine the required number and strength of tiedowns for a load.

Question 19General Knowledge (CDL Manual core section)

A load of steel coils must be secured to prevent movement. Which practice best meets cargo securement requirements?

  1. Rely on the weight of the coils alone
  2. Secure only the front of the load
  3. Use ropes of any strength
  4. Use tiedowns rated for the load and check them during the trip Correct answer.

Explanation

Heavy loads like steel coils require tiedowns rated for the load and periodic checks during transit. Weight alone does not prevent shifting.

Question 20General Knowledge (CDL Manual core section)

What is the recommended following distance for a commercial vehicle traveling at highway speed in good conditions?

  1. Two car lengths
  2. At least one second for every 10 feet of vehicle length Correct answer.
  3. One second
  4. Five feet per mph

Explanation

A common rule is at least one second of following distance for every 10 feet of vehicle length at speeds above 40 mph. This accounts for the longer stopping distance of heavy vehicles.

Question 21General Knowledge (CDL Manual core section)

When is a driver required to place emergency warning devices such as reflective triangles?

  1. Only in construction zones
  2. Only at night
  3. Whenever the vehicle is stopped on a highway or shoulder due to an emergency Correct answer.
  4. Only when carrying hazardous materials

Explanation

Warning devices must be placed when a vehicle is stopped on a highway or shoulder because of an emergency. They alert approaching traffic to the hazard.

Question 22General Knowledge (CDL Manual core section)

A driver must stop at a railroad crossing when:

  1. The crossing has a flashing green light
  2. The crossing is marked with a yield sign
  3. The driver is traveling below 20 mph
  4. The vehicle is carrying passengers or hazardous materials and no flagger is present Correct answer.

Explanation

Certain vehicles, including those carrying passengers or hazardous materials, must stop at railroad crossings unless a flagger or law enforcement directs otherwise. The stop is required regardless of posted signals in those cases.

Question 23General Knowledge (CDL Manual core section)

What should a driver do if the vehicle's brakes become wet and lose effectiveness?

  1. Apply light pressure to dry the brakes while moving slowly Correct answer.
  2. Stop immediately in the travel lane
  3. Continue at the same speed
  4. Pump the brakes repeatedly at highway speed

Explanation

Light brake application at low speed helps dry wet brakes and restore effectiveness. Continuing at speed with reduced braking is unsafe.

Question 24General Knowledge (CDL Manual core section)

Which statement best describes the effect of a vehicle's center of gravity on rollover risk?

  1. A lower center of gravity increases rollover risk
  2. A higher center of gravity reduces rollover risk
  3. Center of gravity has no effect on rollover
  4. A higher center of gravity increases rollover risk in turns Correct answer.

Explanation

A high center of gravity, common in loaded commercial vehicles, makes a vehicle more prone to rollover during turns. Drivers must slow down before curves to counter this effect.

Question 25General Knowledge (CDL Manual core section)

When approaching a curve, what is the recommended sequence for a commercial driver?

  1. Maintain speed and steer sharply
  2. Brake in the curve, then accelerate out
  3. Slow down before the curve, then accelerate gently through it Correct answer.
  4. Accelerate before the curve to build momentum

Explanation

Slowing before entering a curve keeps the vehicle stable and reduces rollover risk. Gentle acceleration through the curve helps maintain control.

Question 26General Knowledge (CDL Manual core section)

Under federal CDL rules, a commercial driver's vehicle is considered to have an out-of-service defect when the driver fails to correct a brake defect that affects braking performance. Which condition most clearly places a CMV out of service for brakes?

  1. A small amount of rust visible on a brake drum surface
  2. A missing brake drum or rotor on a steering-axle wheel Correct answer.
  3. Brake pedal travel of about one inch before resistance
  4. A slight squeal from one rear brake during light application

Explanation

Federal out-of-service criteria treat a missing brake component on a steering-axle wheel as a critical defect because it eliminates braking on a wheel used for steering control. A missing drum or rotor means that wheel provides no braking at all. Minor noise, normal pedal travel, and surface rust do not by themselves meet out-of-service thresholds.

Question 27General Knowledge (CDL Manual core section)

Before driving a CMV, a driver must inspect the coupling system on a tractor-trailer. What confirms that the fifth wheel is properly locked to the kingpin?

  1. The landing gear is raised fully to its highest position
  2. The trailer apron rests flat against the tractor frame
  3. The release handle is fully in and a firm pull on the tractor in low gear shows no separation Correct answer.
  4. The air lines hang free with slack below the coupling

Explanation

The accepted check is to ensure the locking jaws are closed and the release handle is in, then gently pull the tractor forward with the trailer brakes set to confirm the coupling holds. If the trailer does not move relative to the tractor, the kingpin is locked. Visual cues alone, such as apron position, do not prove the jaws have engaged.

Question 28General Knowledge (CDL Manual core section)

A driver is inspecting a CMV and finds the steering wheel has more than the allowed free play. What is the correct interpretation of this finding?

  1. The vehicle is unsafe to operate until the steering defect is repaired Correct answer.
  2. The free play is acceptable if the vehicle is empty
  3. The condition only matters when driving above highway speed
  4. The steering can be used if the driver grips the wheel firmly

Explanation

Excessive steering wheel free play is a defect that reduces steering control and places the vehicle out of service until corrected. Free play limits exist precisely because loose steering linkage can prevent precise directional control. Load condition or driver grip does not cure a mechanical steering defect.

Question 29General Knowledge (CDL Manual core section)

A driver must understand how weight distribution affects vehicle handling. If cargo is loaded so that the rear axle is overloaded beyond its rating, what is the most likely consequence?

  1. Lower center of gravity that eliminates rollover risk
  2. Shorter stopping distance because of added rear weight
  3. Improved traction on the drive axle with no safety drawback
  4. Reduced steering control on the front axle and increased risk of tire failure Correct answer.

Explanation

Overloading the rear axle can lift weight off the steering axle, making steering feel light and less responsive, while overstressing rear tires. Axle and tire ratings exist to keep each component within safe limits. Added rear weight does not shorten stopping distance and does not remove rollover risk.

Question 30General Knowledge (CDL Manual core section)

A driver is preparing to transport a load and must decide how to distribute it. Which practice best supports safe handling?

  1. Load all weight over the rear axle to maximize traction
  2. Distribute cargo so the trailer is loaded only on one side
  3. Place heavier items high to lower the center of gravity
  4. Place heavier items low and centered, and keep weight within axle and tire limits Correct answer.

Explanation

Keeping heavy freight low and centered lowers the center of gravity and helps balance the load across axles. Every axle and tire has a rated capacity that must not be exceeded. Loading high, concentrating on one axle, or loading to one side all increase instability.

Question 31General Knowledge (CDL Manual core section)

While driving, a driver notices the low air pressure warning signal has activated. What should the driver do?

  1. Stop as soon as it is safe and investigate before continuing Correct answer.
  2. Increase engine speed to build pressure while driving
  3. Continue to the next scheduled stop if the gauge is above 60 psi
  4. Shift to a lower gear and keep driving normally

Explanation

The low air pressure warning alerts the driver that air pressure is dropping toward a level where brakes may no longer function properly. The safe response is to stop in a safe location and find the cause before moving on. Continuing to drive or trying to outrun the warning risks brake loss.

Question 32General Knowledge (CDL Manual core section)

A driver must know how to test the service brakes after repairs. What does a proper brake test confirm?

  1. The air compressor builds pressure within a set time
  2. The brakes stop the vehicle evenly and the vehicle does not pull to one side Correct answer.
  3. The parking brake holds on a steep grade
  4. The slack adjusters are fully extended

Explanation

A service brake test checks that the brakes apply and release properly and that the vehicle stops in a straight line without pulling. Pulling to one side suggests uneven braking that needs correction. Parking brake holding, compressor build-up, and slack adjuster position are separate checks.

Question 33General Knowledge (CDL Manual core section)

A driver is approaching a bridge with a posted height limit lower than the vehicle's stated height. What is the correct action?

  1. Assume the posted limit allows a small tolerance
  2. Take an alternate route that provides adequate clearance Correct answer.
  3. Lower tire pressure to reduce overall height
  4. Proceed slowly and watch the trailer roof for contact

Explanation

If the posted clearance is less than the vehicle's height, the vehicle cannot safely pass, so the driver must choose another route. Posted limits are maximum clearances, and there is no allowance for squeezing through. Reducing tire pressure or creeping forward risks a bridge strike.

Question 34General Knowledge (CDL Manual core section)

A driver is traveling in a construction zone where lanes narrow and workers are present. Which behavior is most appropriate?

  1. Follow the vehicle ahead closely to avoid lane changes
  2. Turn on hazard lights and continue at the posted limit
  3. Maintain highway speed to clear the zone quickly
  4. Reduce speed, increase following distance, and stay alert for sudden changes Correct answer.

Explanation

Work zones require lower speed and greater following distance because lanes, signals, and worker positions can change without warning. Extra space gives time to react to sudden stops or merges. Maintaining speed or tailgating reduces the margin needed to avoid crashes.

Question 35General Knowledge (CDL Manual core section)

A driver is driving at night on an unlit rural road and an oncoming vehicle approaches with bright headlights. What should the driver do?

  1. Move toward the center line to widen the gap
  2. Look directly at the oncoming lights to judge distance
  3. Switch on high beams to improve visibility
  4. Look toward the right edge of the lane and reduce speed until the vehicle passes Correct answer.

Explanation

Looking toward the right edge of the lane helps preserve night vision and keeps the vehicle positioned safely while the glare passes. Reducing speed provides more time to react if an obstacle appears. Staring at the lights, using high beams, or drifting toward the center line increases risk.

Question 36General Knowledge (CDL Manual core section)

A driver is about to drive through a tunnel with a low ceiling and narrow lanes. What preparation is most important?

  1. Know the vehicle's height and width and remove sunglasses before entering Correct answer.
  2. Speed up to pass through before traffic builds
  3. Turn on high beams to see the tunnel walls
  4. Open the windows to equalize pressure

Explanation

Tunnels often have restricted height and width, so the driver must know the vehicle's dimensions and confirm clearance. Removing sunglasses before entry helps the eyes adjust to the darker interior. Speeding, using high beams, and opening windows do not address clearance or visibility.

Question 37General Knowledge (CDL Manual core section)

A driver must recognize when a vehicle is placed out of service for a tire defect. Which tire condition meets out-of-service criteria?

  1. A tire with slightly uneven wear across the tread
  2. A front tire with tread separated from the casing Correct answer.
  3. A rear tire with a small nail in the tread that holds air
  4. A tire with a valve cap missing

Explanation

Tread separation on a steering-axle tire is a critical defect because the tire can fail suddenly and cause loss of control. Such a tire places the vehicle out of service until replaced. A small nail that holds air, mild uneven wear, and a missing valve cap do not by themselves meet out-of-service thresholds.

Question 38General Knowledge (CDL Manual core section)

A driver is inspecting the exhaust system before a trip. Which finding requires attention before driving?

  1. A slightly discolored heat shield
  2. A light coating of dust on the outside of the pipe
  3. A loose or leaking exhaust connection near the cab Correct answer.
  4. A new clamp installed at a joint

Explanation

A leaking exhaust connection can allow carbon monoxide and hot gases into the cab or near air intake points, creating a serious hazard. Exhaust systems must be intact and securely connected. Surface dust, discoloration, and a properly installed clamp are not defects.

Question 39General Knowledge (CDL Manual core section)

A driver is checking the engine compartment and finds the coolant level below the minimum mark. What is the best course of action?

  1. Top off with any available liquid to reach the mark
  2. Add the recommended coolant to the proper level before driving Correct answer.
  3. Ignore the level if the temperature gauge is normal
  4. Drive and let the engine warm up to raise the level

Explanation

Low coolant can lead to overheating and engine damage, so it should be brought to the specified level with the correct coolant before the trip. Using random liquids can harm the cooling system. Waiting for warm-up or relying on a gauge does not correct a low level.

Question 40General Knowledge (CDL Manual core section)

A driver is preparing to descend a long mountain grade with a heavy load. Which practice helps prevent brake fade?

  1. Rely on the service brakes continuously to hold a steady speed
  2. Select a lower gear and use engine braking to control speed Correct answer.
  3. Apply the parking brake lightly during the descent
  4. Shift to neutral to coast down the grade

Explanation

On a long downgrade, a low gear and engine braking keep the vehicle at a safe speed without continuous service brake use. Brakes that are applied constantly can overheat and fade, reducing stopping power. Coasting in neutral or dragging the parking brake removes control and overheats components.

Question 41General Knowledge (CDL Manual core section)

A driver is transporting hazardous materials requiring placards. What must the driver do before driving?

  1. Confirm the required placards are displayed and the shipping papers are accessible Correct answer.
  2. Place placards only on the rear of the trailer
  3. Keep shipping papers locked in a toolbox
  4. Remove placards to avoid attracting attention

Explanation

When placards are required, they must be properly displayed on the vehicle and the shipping papers must be within reach for inspectors and emergency responders. Placards belong on both sides and the rear as specified. Hiding papers or removing placards violates hazmat rules.

Question 42General Knowledge (CDL Manual core section)

A driver is hauling a load that extends beyond the rear of the vehicle. What is required during daylight hours?

  1. A white cloth tied near the cab door
  2. No marking if the overhang is less than six feet
  3. A single reflective triangle placed on the cab roof
  4. A red or orange flag at least 18 inches square at the end of the load Correct answer.

Explanation

Loads extending beyond the rear must be marked so other drivers can see the projection. During daylight, a flag of at least 18 inches square at the extreme rear end is the standard marker. Marking the cab or relying on overhang length does not satisfy the requirement.

Question 43General Knowledge (CDL Manual core section)

A driver must check that cargo is secured against shifting. Which condition indicates the securement is inadequate?

  1. The load is centered and within axle limits
  2. The load is covered and the cover is fastened
  3. Tiedowns are loose enough that the load can slide sideways Correct answer.
  4. Tiedowns are tight and attached to rated anchor points

Explanation

Cargo securement must prevent the load from shifting, sliding, or falling. Loose tiedowns that allow sideways movement mean the load is not adequately secured. Tight tiedowns on rated anchors, a fastened cover, and a centered load are all indicators of proper securement.

Question 44General Knowledge (CDL Manual core section)

A driver is driving in heavy rain and the road surface is slick. Which adjustment best reduces the risk of a skid?

  1. Reduce following distance to avoid spray
  2. Brake harder and later to test traction
  3. Accelerate through turns to maintain momentum
  4. Slow down and increase following distance Correct answer.

Explanation

Wet roads reduce traction, so lower speed and a larger following gap give more time to stop and turn without skidding. Hard braking, accelerating through turns, or tailgating all demand more traction than the surface can provide. Smooth, gradual inputs are the safest approach.

Question 45General Knowledge (CDL Manual core section)

A driver is operating a CMV and feels the vehicle begin to drift because of a strong crosswind. What is the safest response?

  1. Accelerate to push through the gust
  2. Steer sharply into the wind to hold the lane
  3. Apply the brakes hard until the wind stops
  4. Reduce speed and make smooth steering corrections Correct answer.

Explanation

Strong crosswinds can push a tall vehicle out of its lane, especially at higher speeds. Slowing down reduces the wind's effect and gives the driver time to make gentle steering corrections. Sharp steering, accelerating, or hard braking can cause loss of control.

Question 46General Knowledge (CDL Manual core section)

A driver is stopped on the shoulder of a highway at night to check a tire. What is the best way to reduce the risk of being struck?

  1. Stand behind the trailer to direct traffic
  2. Turn on hazard lights and place reflective triangles behind the vehicle Correct answer.
  3. Leave all lights off to avoid glare
  4. Place a warning device only in front of the vehicle

Explanation

When stopped on the shoulder, hazard lights and reflective triangles warn approaching traffic of the stopped vehicle. Placing triangles behind the vehicle gives drivers time to move over. Standing in traffic or leaving lights off makes the vehicle harder to see and increases danger.

Question 47General Knowledge (CDL Manual core section)

A driver is checking the vehicle's lighting system before a night trip. Which condition requires correction?

  1. A clearance light that does not illuminate when switched on Correct answer.
  2. A marker light with a clean lens
  3. A turn signal that flashes at a normal rate
  4. A headlight aimed slightly lower than the other

Explanation

All required lights must function for the vehicle to be operated safely, particularly at night. A clearance light that fails to illuminate is a defect that must be repaired. Properly aimed headlights, normal turn signal flashing, and clean lenses are acceptable conditions.

Question 48General Knowledge (CDL Manual core section)

A driver is about to back a CMV into a loading dock. Which practice best supports a safe backing maneuver?

  1. Rely only on the mirrors and skip the walk-around
  2. Sound the horn continuously and back without checking
  3. Back quickly to minimize time in the blind spot
  4. Use a spotter and get out to check the area if no spotter is available Correct answer.

Explanation

Backing a large vehicle creates large blind spots, so a spotter or a personal walk-around check is the best way to confirm the path is clear. Backing quickly or relying only on mirrors increases the chance of striking a person or object. Horn use does not replace a visual check.

Question 49General Knowledge (CDL Manual core section)

A driver has been diagnosed with a condition that may affect the ability to drive safely. Under CDL medical requirements, what should the driver do?

  1. Self-treat the condition and keep driving
  2. Continue driving until the medical card expires
  3. Ask a coworker to certify fitness to drive
  4. Report the condition and obtain medical clearance before continuing to drive Correct answer.

Explanation

A driver must meet medical fitness standards to hold a CDL, and a new condition that could impair driving must be evaluated by a qualified examiner. Driving until the card expires or relying on self-treatment risks operating while medically unqualified. Coworkers cannot certify fitness.

Question 50General Knowledge (CDL Manual core section)

A driver is completing a pre-trip inspection and checks the fire extinguisher. Which condition indicates the extinguisher is ready for use?

  1. The extinguisher is stored loose in a side box
  2. The gauge reads in the operable range and the extinguisher is securely mounted Correct answer.
  3. The pin is removed and the seal is broken
  4. The gauge needle rests below the green zone

Explanation

A fire extinguisher must be charged, with the gauge in the operable range, and securely mounted so it is accessible and will not become a projectile. A loose extinguisher, a low gauge reading, or a missing pin and broken seal means it is not ready for use.