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Nebraska CDL General Knowledge study materials
Nebraska CDL General Knowledge study resources

Nebraska CDL General Knowledge practice questions

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Question 1General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

During a pre-trip inspection, what is the maximum allowable air pressure loss for a combination vehicle with the engine off and the service brake held applied for one minute after the initial pressure drop?

  1. No more than 4 psi Correct answer.
  2. No more than 3 psi
  3. No more than 1 psi
  4. No more than 2 psi

Explanation

For a combination vehicle with the engine off and the service brake held applied, air pressure must not drop more than 4 psi in one minute after the initial pressure drop stabilizes. This is the maximum allowable loss, not a required minimum. The applied-brake limit for a single vehicle is 3 psi.

Question 2General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the minimum tread depth required for front steering axle tires on a commercial vehicle?

  1. 8/32 inch
  2. 2/32 inch
  3. 6/32 inch
  4. 4/32 inch Correct answer.

Explanation

Front steering axle tires must have at least 4/32 inch of tread depth. All other tires on the vehicle must have at least 2/32 inch. Steering tires carry the most control responsibility, so they get the stricter standard.

Question 3General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

When you must drive through a curve, which technique helps you maintain control of a large vehicle?

  1. Accelerate before the curve and hold speed through the turn
  2. Brake firmly while turning through the curve
  3. Slow down before the curve, then accelerate gently through it Correct answer.
  4. Shift to neutral and coast through the curve

Explanation

The safest approach is to reduce speed before entering the curve and then accelerate gently once inside it. Braking hard in a curve can cause a skid or rollover because of the vehicle's high center of gravity. Coasting in neutral removes engine control and is unsafe.

Question 4General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the proper procedure for shifting into a lower gear on a downgrade?

  1. Shift while braking hard on the grade
  2. Shift before the downgrade begins Correct answer.
  3. Shift only after reaching the bottom of the grade
  4. Shift after the vehicle begins to speed up

Explanation

You should select a lower gear before starting down the grade so engine braking helps control speed. Waiting until the vehicle speeds up makes it harder to complete the shift and can overheat the brakes. Braking hard while shifting is unsafe.

Question 5General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

When backing a tractor-trailer, which method gives you the greatest control?

  1. Back straight with mirrors only
  2. Back toward the driver's side (left) Correct answer.
  3. Back toward the passenger's side (right)
  4. Back using the convex mirrors only

Explanation

Backing toward the driver's side allows you to see the rear of the trailer in your left mirror and keeps the maneuver more controllable. Backing toward the right side is harder because visibility is limited. Use both mirrors and get out to check if unsure.

Question 6General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the recommended following distance for a commercial vehicle traveling under 40 mph in ideal conditions?

  1. Four seconds Correct answer.
  2. Six seconds
  3. Two seconds
  4. One second

Explanation

The manual recommends at least one second for each 10 feet of vehicle length at speeds below 40 mph. For a 40-foot vehicle, that is four seconds. Add one second for speeds above 40 mph.

Question 7General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

How does the total stopping distance of a loaded commercial vehicle compare with that of an empty one?

  1. It is longer because of greater momentum Correct answer.
  2. It is shorter because brakes grip better
  3. It is the same regardless of load
  4. It is shorter because weight increases traction

Explanation

A heavier vehicle has more momentum, so it takes longer to stop. Brakes must overcome that momentum, increasing stopping distance. Load does not reduce stopping distance.

Question 8General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

Which action is required before entering a railroad crossing in a commercial vehicle?

  1. Sound the horn and proceed without stopping
  2. Stop only if a train is visible
  3. Slow down and look both ways without stopping
  4. Stop, look both ways, and listen before proceeding Correct answer.

Explanation

Commercial drivers must stop at railroad crossings, look both ways, and listen before crossing, unless the crossing is exempt. This applies even when no train is visible. Proceeding without stopping is unsafe and a violation.

Question 9General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What should you do if your vehicle's brakes fail while driving?

  1. Pump the brakes and downshift to a lower gear Correct answer.
  2. Turn off the engine immediately
  3. Release the parking brake and coast
  4. Accelerate to clear traffic

Explanation

If brakes fail, pump the brakes to build pressure and downshift to use engine braking. You can also use the emergency brake gradually. Turning off the engine can lock the steering and is dangerous.

Question 10General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

When a tire blows out at highway speed, what is the correct first response?

  1. Brake hard immediately
  2. Accelerate to stabilize the vehicle
  3. Turn sharply to the shoulder
  4. Hold the steering wheel firmly and steer straight Correct answer.

Explanation

Hold the steering wheel firmly and keep the vehicle straight while easing off the accelerator. Braking hard or turning sharply can cause a loss of control. After slowing, pull off the road safely.

Question 11General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the purpose of the retarder on a commercial vehicle?

  1. To improve fuel economy at high speed
  2. To increase engine power on grades
  3. To lock the wheels during emergency stops
  4. To help slow the vehicle on downgrades Correct answer.

Explanation

A retarder helps slow the vehicle on downgrades, reducing reliance on the service brakes. It is especially useful on long grades where brakes can overheat. It does not lock wheels or increase power.

Question 12General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the correct way to check for a hydraulic brake leak during a pre-trip inspection?

  1. Release the pedal and watch the gauge
  2. Tap the pedal lightly and check for vibration
  3. Pump the brake pedal and listen for hissing
  4. Press the pedal firmly and hold it for a few seconds Correct answer.

Explanation

Press the brake pedal firmly and hold it for a few seconds; if it fades, there may be a leak. This checks for hydraulic pressure loss. Listening for hissing checks air brakes, not hydraulic brakes.

Question 13General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

How should cargo be secured in a commercial vehicle?

  1. With tiedowns that meet the working load limit Correct answer.
  2. With the tailgate closed and no tiedowns
  3. With the cargo pushed against the cab
  4. With ropes tied to the vehicle frame

Explanation

Cargo must be secured with tiedowns rated at or above the working load limit. Ropes tied to the frame may not meet the required strength. Pushing cargo against the cab or relying on the tailgate is not sufficient.

Question 14General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the maximum number of hours a property-carrying driver may drive after 10 consecutive hours off duty?

  1. 10 hours
  2. 11 hours Correct answer.
  3. 14 hours
  4. 8 hours

Explanation

Property-carrying drivers may drive a maximum of 11 hours after 10 consecutive hours off duty. The 14-hour window includes all on-duty time. The 60/70-hour limit applies over 7 or 8 days.

Question 15General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the purpose of the whistleblower protection rule for commercial drivers?

  1. To allow drivers to refuse to drive unsafe vehicles without retaliation Correct answer.
  2. To let drivers skip pre-trip inspections
  3. To permit drivers to exceed speed limits in emergencies
  4. To allow drivers to falsify logs

Explanation

Whistleblower protection prevents retaliation against drivers who report unsafe vehicles or refuse to drive them. It encourages safety compliance. It does not permit skipping inspections, speeding, or falsifying records.

Question 16General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

When driving in fog, which lights should you use?

  1. Hazard lights while moving
  2. Low-beam headlights Correct answer.
  3. High-beam headlights
  4. Parking lights only

Explanation

Use low-beam headlights in fog because high beams reflect off the fog and reduce visibility. Parking lights alone are not bright enough. Hazard lights while moving can confuse other drivers.

Question 17General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the correct action when hydroplaning occurs?

  1. Turn sharply toward the shoulder
  2. Accelerate to push through the water
  3. Ease off the accelerator and steer straight Correct answer.
  4. Brake hard to regain traction

Explanation

Ease off the accelerator and keep the steering straight until traction returns. Braking hard or turning sharply can cause a skid. Hydroplaning happens when tires ride on a film of water.

Question 18General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What should you do if you are being tailgated by another vehicle?

  1. Increase your following distance ahead and let the driver pass Correct answer.
  2. Speed up to increase the gap
  3. Turn on your high beams
  4. Brake suddenly to warn the driver

Explanation

Increase your following distance ahead so you can stop gradually and give the tailgater room. Let the driver pass when safe. Braking suddenly or speeding up increases danger.

Question 19General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the correct way to use a fire extinguisher on a vehicle fire?

  1. Aim at the base of the fire and sweep side to side Correct answer.
  2. Aim at the flames from a distance
  3. Use water first, then the extinguisher
  4. Spray upward into the smoke

Explanation

Aim at the base of the fire and sweep side to side to smother it. Aiming at the flames wastes the agent. Water should not be used on fuel or electrical fires.

Question 20General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What does the term 'center of gravity' mean when loading cargo?

  1. The highest point of the cargo
  2. The lowest point of the trailer
  3. The point where the weight is balanced Correct answer.
  4. The heaviest point of the load

Explanation

Center of gravity is the point where the weight is balanced. A high center of gravity makes a vehicle more likely to roll over. Keeping the load low and balanced improves stability.

Question 21General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the purpose of the pre-trip inspection?

  1. To plan the route
  2. To check the vehicle for safety defects before driving Correct answer.
  3. To verify the cargo weight
  4. To calculate fuel costs

Explanation

The pre-trip inspection checks the vehicle for safety defects before driving. It covers brakes, tires, lights, and other critical items. It does not verify cargo weight or plan routes.

Question 22General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

When driving a vehicle with a high center of gravity, which action increases the risk of rollover?

  1. Keeping the load low
  2. Turning sharply at speed Correct answer.
  3. Increasing following distance
  4. Slowing before a curve

Explanation

Turning sharply at speed increases centrifugal force and raises rollover risk, especially with a high center of gravity. Slowing before curves and keeping the load low reduce risk. Following distance does not affect rollover.

Question 23General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the correct action when an emergency vehicle approaches with lights and siren on?

  1. Pull to the right and stop Correct answer.
  2. Speed up to clear the lane
  3. Continue at the same speed
  4. Stop in the middle of the road

Explanation

Pull to the right and stop to let the emergency vehicle pass. Speeding up or stopping in the road can block it. Continuing at the same speed may delay the emergency response.

Question 24General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What does the term 'space cushion' mean in defensive driving?

  1. The gap between the cab and trailer
  2. The cargo space in the trailer
  3. The braking distance on wet roads
  4. The distance between your vehicle and others Correct answer.

Explanation

A space cushion is the distance between your vehicle and other vehicles, giving you room to react. Maintaining it reduces collision risk. It is not cargo space or a cab-trailer gap.

Question 25General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the correct procedure when driving through a work zone with reduced speed limits?

  1. Maintain the posted speed limit for the highway
  2. Drive on the shoulder to avoid workers
  3. Slow to the posted work zone speed and watch for workers Correct answer.
  4. Ignore the work zone signs if no workers are visible

Explanation

Slow to the posted work zone speed and watch for workers and equipment. Work zone limits apply even if no workers are visible. Driving on the shoulder is unsafe.

Question 26General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

During a pre-trip inspection of a tractor-trailer, you check the coupling system. Which condition indicates the fifth wheel is properly locked?

  1. The trailer apron rests on top of the fifth wheel plate.
  2. The release handle is pushed in and the safety latch is over the handle. Correct answer.
  3. The release handle is pulled out and the safety latch is open.
  4. The air lines are connected but the electrical cord is unplugged.

Explanation

After coupling, the release handle must be pushed fully in and the safety latch must be closed over it; a gentle pull with the tractor in low gear (tug test) confirms the jaws have locked. The handle position and latch are the visual confirmation that the locking jaws have closed around the kingpin.

Question 27General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

Before backing a commercial vehicle, what is the safest first step?

  1. Back quickly to reduce the time spent in reverse.
  2. Rely on the mirrors alone since they cover all blind spots.
  3. Check behind the vehicle and use a helper whenever possible. Correct answer.
  4. Sound the horn twice and back immediately.

Explanation

Backing is one of the highest-risk maneuvers for large vehicles because of large blind spots. Walk around or check behind the vehicle before moving and use a helper whenever one is available, stopping immediately if you lose sight of the helper.

Question 28General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

When starting from a stop on an upgrade with a manual transmission, why should you engage the clutch gradually while releasing the parking brake?

  1. To prevent the vehicle from rolling backward before the engine pulls. Correct answer.
  2. To keep the engine RPM at the redline for maximum power.
  3. To allow the transmission to shift into a higher gear automatically.
  4. To test whether the parking brake is holding.

Explanation

On a hill, the vehicle tends to roll backward as you release the brake. Engaging the clutch smoothly while releasing the parking brake lets the engine begin pulling before the vehicle can roll, preventing a rollback into whatever is behind you.

Question 29General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the proper way to downshift a manual transmission as you slow for a downgrade?

  1. Skip gears and shift directly from the highest gear to the lowest.
  2. Hold the clutch in and coast with the transmission in neutral.
  3. Shift into reverse to use engine braking.
  4. Shift down one gear at a time, matching engine speed to road speed. Correct answer.

Explanation

Shifting down one gear at a time and matching engine speed to road speed keeps the drivetrain synchronized and avoids over-revving or damaging the transmission. Coasting in neutral or skipping gears removes control and can cause a loss of braking from the engine.

Question 30General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

How does a commercial driver use the stab braking method to control speed on a long downgrade?

  1. Use the trailer brakes only and leave the tractor brakes off.
  2. Apply the brakes firmly to reduce speed about 5 mph below the safe speed, then release and repeat. Correct answer.
  3. Shift to neutral and rely on the brakes alone.
  4. Apply light steady pressure to the brakes for the entire descent.

Explanation

Stab braking means applying the brakes hard enough to slow the vehicle, releasing them when the speed drops below your target, and repeating as speed builds again. This lets the brakes cool between applications and avoids overheating that causes fade.

Question 31General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

At highway speed, how much space should you keep in front of a commercial vehicle to allow for reaction and stopping distance?

  1. No set gap; follow as closely as traffic allows.
  2. Half the length of the vehicle at any speed.
  3. A fixed gap of two car lengths regardless of speed.
  4. One second for every 10 feet of vehicle length, plus one second for speeds above 40 mph. Correct answer.

Explanation

The rule of thumb is one second of following distance for each 10 feet of vehicle length at speeds under 40 mph, and one additional second when traveling above 40 mph. This accounts for the longer stopping distance of a heavy vehicle.

Question 32General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

How should a driver look ahead when scanning the road while operating a commercial vehicle?

  1. Focus only on the bumper of the vehicle directly ahead.
  2. Look about one vehicle length ahead at all times.
  3. Watch the rearview mirrors exclusively.
  4. Look 12 to 15 seconds ahead of the vehicle along the road. Correct answer.

Explanation

Scanning 12 to 15 seconds ahead gives you time to spot hazards, plan lane changes, and adjust speed smoothly. At highway speed that distance is roughly a quarter mile, which is needed because a loaded truck takes far longer to stop than a car.

Question 33General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

When must a commercial driver use four-way flashers while driving?

  1. Only when driving in rain or snow.
  2. Whenever the driver plans to change lanes.
  3. When the vehicle is stopped or moving slowly enough to be a hazard to other traffic. Correct answer.
  4. Whenever the vehicle is traveling below the posted speed limit.

Explanation

Four-way flashers warn other drivers that your vehicle is a hazard, typically when stopped on or near the roadway or moving well below the normal traffic speed, such as on a steep grade. They are not a general-purpose signal for lane changes or ordinary slow driving.

Question 34General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the correct way to handle a curve while driving a commercial vehicle?

  1. Slow to a safe speed before the curve, then accelerate gently through it. Correct answer.
  2. Shift to neutral and coast around the curve.
  3. Maintain highway speed and rely on the tires to hold.
  4. Brake hard while in the middle of the curve.

Explanation

Centrifugal force pushes a heavy vehicle toward the outside of a curve, and the effect grows with speed. Slow down before entering the curve while the vehicle is still traveling straight, then accelerate gently once through the curve to maintain control.

Question 35General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

When driving at night, at what point should you dim your high beams for oncoming traffic?

  1. Never, because commercial vehicles are exempt.
  2. Only after the oncoming vehicle has passed.
  3. Within 50 feet of an oncoming vehicle.
  4. Within 500 feet of an oncoming vehicle. Correct answer.

Explanation

High beams must be dimmed within 500 feet of an oncoming vehicle so the other driver is not blinded. Dim them sooner if the other driver appears affected, and also dim within 200 feet when following another vehicle.

Question 36General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

How should a driver use the mirrors to monitor the sides and rear of a commercial vehicle?

  1. Adjust them so the trailer is fully visible in each mirror.
  2. Rely on them instead of turning your head at intersections.
  3. Check them regularly, including before and during turns and lane changes. Correct answer.
  4. Check them only when preparing to change lanes.

Explanation

Mirrors should be checked regularly, not just before a lane change, because situations develop quickly around a large vehicle. They also help you confirm the trailer is tracking properly and that no vehicle is in a blind spot during a turn.

Question 37General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

A front tire of your commercial vehicle goes flat while you are traveling at highway speed. What should you do first?

  1. Brake hard immediately to stop as quickly as possible.
  2. Accelerate to keep the vehicle from pulling to one side.
  3. Steer sharply toward the shoulder to get off the road.
  4. Hold the steering wheel firmly and keep the vehicle straight while slowing gradually. Correct answer.

Explanation

When a steer tire fails, the vehicle pulls hard toward the flat side. Grip the wheel firmly, keep the vehicle straight, and ease off the accelerator so speed drops gradually before moving to the shoulder. Hard braking or sharp steering can cause a loss of control or rollover.

Question 38General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

When a commercial vehicle begins to skid on a wet road, what is the recommended response?

  1. Turn the steering wheel in the direction the rear of the vehicle is sliding. Correct answer.
  2. Accelerate to pull the vehicle out of the skid.
  3. Turn the steering wheel opposite the direction of the slide.
  4. Apply the brakes firmly and hold the wheel straight.

Explanation

In a skid, steer in the direction the rear of the vehicle is sliding so the wheels realign with the direction of travel and the vehicle straightens out. Avoid hard braking, which can worsen the skid, and ease off the accelerator.

Question 39General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What should a driver do if a load shifts suddenly while the vehicle is moving?

  1. Brake hard and steer to the shoulder immediately.
  2. Reduce speed gradually and pull off the road at the first safe place to check the load. Correct answer.
  3. Continue at the same speed until the next scheduled stop.
  4. Speed up to stabilize the load.

Explanation

A shifted load changes the vehicle's weight distribution and handling, so you should slow gradually and stop at the first safe location to inspect and secure it. Sudden braking or steering with an unstable load can cause a rollover.

Question 40General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

How should a driver check that cargo is secure during a trip?

  1. Once every 24 hours.
  2. Only after the vehicle has been parked overnight.
  3. Only at the start of the trip before departure.
  4. At the start, after the first 50 miles, and every 150 miles or 3 hours thereafter. Correct answer.

Explanation

Cargo securement must be checked at the beginning of the trip, again within the first 50 miles, and then at intervals of no more than 150 miles or 3 hours, whichever comes first. Loads can settle and straps can loosen as the vehicle travels.

Question 41General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the maximum number of hours a property-carrying driver may be on duty after 10 consecutive hours off duty before a break is required?

  1. 14 hours Correct answer.
  2. 11 hours
  3. 8 hours
  4. 16 hours

Explanation

A property-carrying driver may not drive after the 14th consecutive hour on duty following 10 consecutive hours off. The 11-hour limit applies to driving time, while the 14-hour limit applies to the on-duty window, and a 30-minute break is required after 8 cumulative hours of driving.

Question 42General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the purpose of completing a driver vehicle inspection report at the end of the day?

  1. To record the driver's fuel purchases.
  2. To log the miles driven for payroll.
  3. To report any defects that could affect the safety of the vehicle. Correct answer.
  4. To document the cargo weight for billing.

Explanation

The driver vehicle inspection report records any defects discovered during the day's operation so the carrier can repair them before the vehicle is dispatched again. It is a safety document, not a record of fuel, payroll, or billing.

Question 43General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

A commercial driver is convicted of a traffic violation while operating a commercial motor vehicle. What is the general requirement regarding notification to the employer?

  1. The driver has no obligation to report the conviction.
  2. The driver must notify the employer only at the next annual review.
  3. The driver must notify the employer only if the violation involved a crash.
  4. The driver must notify the employer within 30 days of the conviction. Correct answer.

Explanation

A driver convicted of a traffic violation while operating a commercial motor vehicle must notify the employer within 30 days of the conviction. Employers need this information to maintain accurate safety records and to meet their own reporting obligations.

Question 44General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What does the term 'on-duty time' include for a property-carrying driver?

  1. Only the time spent loading and unloading cargo.
  2. Only the time spent behind the wheel plus meal breaks.
  3. Only the time spent actually driving the vehicle.
  4. All time from when the driver begins work until released, including driving and other work. Correct answer.

Explanation

On-duty time covers all time from the start of work until the driver is released, including driving, loading, inspections, fueling, and waiting to be dispatched. It is broader than driving time alone, and the 14-hour window is measured against it.

Question 45General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

When must a commercial driver place the vehicle's emergency warning devices out after stopping on a two-lane road?

  1. Whenever the vehicle is stopped on the roadway or shoulder, day or night. Correct answer.
  2. Only when the vehicle is disabled and cannot be moved.
  3. Only at night or in bad weather.
  4. Only when a police officer requests it.

Explanation

Warning devices such as reflective triangles must be placed whenever a commercial vehicle is stopped on the roadway or shoulder, regardless of the time of day. They alert approaching traffic to the stopped vehicle and reduce the risk of a rear-end collision.

Question 46General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

How far behind the vehicle should the first reflective triangle be placed on a two-lane road?

  1. 500 feet
  2. 100 feet
  3. 40 feet Correct answer.
  4. 10 feet

Explanation

On a two-lane road, place the first triangle 10 feet behind the vehicle, the second 40 feet behind the vehicle, and the third on the traffic side about 40 feet behind the vehicle. On a divided highway the triangles are spaced differently because traffic approaches from one direction.

Question 47General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the correct way to cross railroad tracks in a commercial vehicle carrying hazardous materials?

  1. Cross without stopping if the crossing has a green light.
  2. Stop before the tracks, check both directions, and proceed only when clear. Correct answer.
  3. Follow the vehicle ahead closely to cross at the same time.
  4. Speed up to cross as quickly as possible.

Explanation

Vehicles carrying hazardous materials must stop before railroad tracks, look and listen for trains, and proceed only when the tracks are clear. Following another vehicle closely can leave you stopped on the tracks if that vehicle stalls.

Question 48General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What should a driver do when a front wheel is caught in a soft shoulder and the vehicle begins to pull off the pavement?

  1. Grip the wheel, ease off the accelerator, and steer gently back onto the pavement once speed is reduced. Correct answer.
  2. Accelerate to pull the wheel out of the soft material.
  3. Brake hard and steer sharply back onto the pavement.
  4. Turn the wheel away from the pavement and ride the shoulder to a stop.

Explanation

When a wheel drops onto a soft shoulder, the vehicle pulls toward that side. Grip the wheel firmly, slow gradually, and steer back onto the pavement gently once speed is reduced. Hard braking or sharp steering can cause the vehicle to swerve or roll over.

Question 49General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

What is the safest action when a commercial vehicle's engine overheats on a long climb?

  1. Continue climbing to reach the top before stopping.
  2. Pour cold water on the engine block to cool it quickly.
  3. Open the radiator cap immediately to release pressure.
  4. Pull off the road at a safe place, shut off the engine, and let it cool before checking. Correct answer.

Explanation

An overheating engine should be shut down at a safe location and allowed to cool before any inspection. Opening the radiator cap while the system is hot can release scalding coolant, and sudden cooling can crack engine components.

Question 50General Knowledge (CDL Manual core: vehicle inspection, basic control, shifting, backing, speed/space management, hazard perception, emergency procedures, cargo, hours of service, whistleblower/other regulations)

During a pre-trip inspection, where should you check the slack adjusters on a vehicle with air brakes?

  1. At the treadle valve inside the cab, while an assistant holds the pedal
  2. At the air compressor outlet, with the engine running at high idle
  3. At the brake chamber push rod, with the brakes released and the wheels chocked Correct answer.
  4. At the relay valve under the frame, with the parking brake set

Explanation

Slack adjusters are checked at the push rod with the brakes released and the wheels chocked so the vehicle cannot roll. Pulling each rod by hand shows whether the travel is within the limit marked on the chamber. An assistant is not needed for this check.