CDL Safe Driving

Seeing, communicating, managing speed and space, mountain driving, railroad crossings, fatigue and hazards specific to large vehicles.

132 practice questions with answers. These rules are the same in every state.

CDL Safe Driving quiz

Answer at your own pace. After each question you see the correct answer and why, and at the end a review of what you missed.

Quick quiz: 10 random questions on cdl safe driving; pass with 8 correct.

CDL Safe Driving questions with answers

Experienced commercial drivers scan the road ahead by roughly how much travel time?
1. About 2 to 3 seconds
2. About 12 to 15 seconds
3. About 5 to 6 seconds
4. About 30 to 40 seconds
Show answer

Answer B: About 12 to 15 seconds

Looking 12 to 15 seconds ahead gives a heavy vehicle enough room to slow or change lanes smoothly instead of reacting late.
Below 40 mph, what following distance does the standard commercial rule of thumb call for?
1. One second, no matter how long the vehicle is
2. Two seconds for every 10 feet of vehicle length
3. One second for every 10 feet of vehicle length
4. Half a second for every 10 feet of vehicle length
Show answer

Answer C: One second for every 10 feet of vehicle length

The base rule allows one second of space for each 10 feet of vehicle length while speed stays under 40 mph.

Source: fmcsa.dot.gov
A 60 foot combination traveling above 40 mph should hold how many seconds of following distance?
1. Four seconds
2. Five seconds
3. Six seconds
4. Seven seconds
Show answer

Answer D: Seven seconds

Six seconds cover the 60 feet of vehicle length, and one extra second is added because the speed is above 40 mph.

Source: fmcsa.dot.gov
At 55 mph on dry pavement with good brakes, total stopping distance for a loaded heavy vehicle is roughly what?
1. About 100 feet
2. About 400 feet or more
3. About 200 feet
4. About 60 feet
Show answer

Answer B: About 400 feet or more

Perception, reaction, and braking together add up to roughly 400 feet or more, farther than the length of a football field.

Source: fmcsa.dot.gov
When speed doubles, what happens to braking distance?
1. It stays about the same
2. It grows by about half
3. It doubles
4. It becomes roughly four times as long
Show answer

Answer D: It becomes roughly four times as long

Braking distance rises with the square of speed, so twice the speed needs about four times the distance to stop.

Source: fmcsa.dot.gov
Compared with a fully loaded one, an empty truck under hard braking will often do what?
1. Need a longer distance to stop because traction is poor
2. Stop in about half the distance every time, whatever the surface
3. Be unable to lock its wheels
4. Handle exactly the same as when it is fully loaded
Show answer

Answer A: Need a longer distance to stop because traction is poor

Stiff suspension and little weight over the tires reduce grip, so the wheels lock early and the vehicle can take longer to stop.
On a wet road, a commercial driver should reduce speed by roughly how much?
1. By about one tenth
2. By about two thirds
3. By about one third
4. No reduction is needed with new tires
Show answer

Answer C: By about one third

Cutting speed by roughly a third, for example from 55 to about 35 mph, restores a margin for the traction lost on a wet surface.

Source: fmcsa.dot.gov
On packed snow, how much should a commercial driver reduce speed?
1. By about one tenth
2. By about one fifth
3. No reduction is needed once chains are fitted
4. By about one half or more
Show answer

Answer D: By about one half or more

Packed snow costs far more traction than rain, so speed should be cut by half or more.

Source: fmcsa.dot.gov
With water standing on the road, hydroplaning can begin at speeds as low as what?
1. 55 mph
2. 65 mph
3. 45 mph
4. 30 mph
Show answer

Answer D: 30 mph

When enough water covers the surface, the tires can ride up on it and lose contact at speeds as low as 30 mph.

Source: fmcsa.dot.gov
When should a driver select the gear for a long, steep downgrade?
1. After the vehicle has picked up speed
2. Before starting down the grade
3. At about the midpoint of the grade
4. Only if the brakes start to fade
Show answer

Answer B: Before starting down the grade

The low gear has to be chosen before the descent, because a heavy vehicle gaining speed may refuse to shift down at all.
Using the snub braking method on a downgrade, when does the driver release the brakes?
1. After speed has dropped about 5 mph below the safe speed
2. Immediately after the brakes are first applied
3. Only at the bottom of the grade
4. When the engine reaches its maximum rpm
Show answer

Answer A: After speed has dropped about 5 mph below the safe speed

The driver brakes firmly to about 5 mph under the chosen safe speed, releases to let the brakes cool, then repeats when the safe speed returns.
What is the purpose of an escape ramp on a mountain grade?
1. To give slow vehicles a place to pull over and be passed safely
2. To provide a place to re-check the load
3. To stop a runaway vehicle without injuring the driver
4. To weigh vehicles and check their brakes before the descent
Show answer

Answer C: To stop a runaway vehicle without injuring the driver

Escape ramps use soft material or a steep upgrade to bring a vehicle with failed brakes to a controlled stop.
A commercial vehicle stops on the shoulder of a one-way or divided highway. Where do the three warning devices go?
1. At 10 feet, 100 feet, and 200 feet back toward approaching traffic
2. At 10 feet, 50 feet, and 100 feet back toward approaching traffic
3. All three within 10 feet of the vehicle
4. One device only, placed 500 feet back
Show answer

Answer A: At 10 feet, 100 feet, and 200 feet back toward approaching traffic

Traffic arrives from one direction only, so all three devices are set back toward it at 10, 100, and 200 feet, and they must be out within ten minutes.

Source: csa.fmcsa.dot.gov
A commercial vehicle stops on the shoulder of an undivided two-lane road that carries traffic in both directions. Where do the warning devices go?
1. All three devices 200 feet behind the vehicle
2. Within 10 feet of the vehicle, plus 100 feet to the front and 100 feet to the rear
3. At 10, 100, and 200 feet to the rear only
4. One device 500 feet ahead of the vehicle
Show answer

Answer B: Within 10 feet of the vehicle, plus 100 feet to the front and 100 feet to the rear

On a two-way road the devices must mark the vehicle itself and warn traffic approaching from each direction, and they must be in place within ten minutes.

Source: csa.fmcsa.dot.gov
How does a driver measure following distance in seconds?
1. Wait for the vehicle ahead to pass a fixed roadside object, then count the seconds until the front of your vehicle reaches the same object
2. Divide the speed in miles per hour by the length of the vehicle
3. Count the number of lane markings between the two vehicles
4. Read the gap from the trip odometer
Show answer

Answer A: Wait for the vehicle ahead to pass a fixed roadside object, then count the seconds until the front of your vehicle reaches the same object

Counting from the moment the vehicle ahead passes a landmark until you reach it turns a gap you cannot judge in feet into a number of seconds.

Source: dds.georgia.gov
Study tip. Rule out the options you know are wrong first. Two plausible answers are easier to choose between than four.
What should a driver assume about the height posted at a bridge or an overpass?
1. That it is measured with the road covered in snow
2. That it may be wrong, because repaving or packed snow can leave less clearance than the sign shows
3. That it always includes a safety margin of one foot
4. That it applies only to loaded vehicles
Show answer

Answer B: That it may be wrong, because repaving or packed snow can leave less clearance than the sign shows

Resurfacing and packed snow raise the road under the structure, so the real clearance can be lower than the posted figure.

Source: oregon.gov
Why does a heavy vehicle need a much larger gap than a car in order to cross or enter traffic?
1. Because its mirrors give a narrower view of the cross traffic
2. Because its turn signals cancel more slowly
3. Because it accelerates slowly and needs far more road and time to clear the intersection
4. Because its parking brake takes longer to release than the parking brake on a passenger car does
Show answer

Answer C: Because it accelerates slowly and needs far more road and time to clear the intersection

Slow acceleration combined with the length of the vehicle means a gap that would feel comfortable in a car is nowhere near enough.

Source: oregon.gov
Why should a driver avoid traveling alongside another vehicle for any length of time?
1. Fuel consumption rises sharply in that position
2. The other driver is not allowed to pass or change lanes while you are beside them
3. The mirrors vibrate whenever two heavy vehicles run side by side
4. You lose your escape route and you may be sitting in the other driver blind spot
Show answer

Answer D: You lose your escape route and you may be sitting in the other driver blind spot

Running beside someone leaves nowhere to move if you have to change lanes, and the other driver may not know you are there at all.
A car is following you far too closely. What is the safest response?
1. Open up more space ahead so you can slow gradually, avoid sudden changes, and do not speed up
2. Flash the brake lights repeatedly until the driver behind you drops back to a safe following distance
3. Increase speed steadily until the driver behind you falls back
4. Move onto the shoulder and keep driving there
Show answer

Answer A: Open up more space ahead so you can slow gradually, avoid sudden changes, and do not speed up

Extra room in front lets you slow smoothly instead of braking hard, which is exactly what the driver behind cannot cope with.

Source: dds.georgia.gov
How should a commercial driver treat the speed posted for a curve?
1. As a target speed to hold exactly all the way through the curve
2. As a limit set for cars in good conditions, so a heavy or tall load calls for a lower speed
3. As a figure that applies only after dark
4. As advice that heavy vehicles are allowed to exceed once the load has been properly secured and checked
Show answer

Answer B: As a limit set for cars in good conditions, so a heavy or tall load calls for a lower speed

Posted curve speeds are based on passenger vehicles in good conditions, and a tall or heavy load can roll over well below that speed.

Source: dds.georgia.gov
How far ahead can a driver see with low beams and with high beams?
1. About 100 feet with low beams and about 200 feet with high beams
2. About 500 feet with low beams and about 1,000 feet with high beams
3. About 250 feet with low beams and about 350 to 500 feet with high beams
4. The same distance with both, because only the aim changes
Show answer

Answer C: About 250 feet with low beams and about 350 to 500 feet with high beams

Low beams reach roughly 250 feet and high beams roughly 350 to 500 feet, and speed at night has to stay inside the distance the lights really show.

Source: dds.georgia.gov
Within what distance should high beams be lowered at night?
1. Within 100 feet of an oncoming vehicle only
2. Within 200 feet of any vehicle
3. Within 1,000 feet of an oncoming vehicle only
4. Within about 500 feet of an oncoming vehicle and within about 500 feet of a vehicle you are following
Show answer

Answer D: Within about 500 feet of an oncoming vehicle and within about 500 feet of a vehicle you are following

High beams blind other drivers at close range, so they are lowered at roughly the same distance whether the other vehicle is coming toward you or is ahead of you.

Source: dds.georgia.gov
Which lights should be used in fog, by day or by night?
1. Low beams and fog lights, together with the four-way flashers
2. High beams, so the light carries farther through the water droplets
3. Marker lamps only
4. No lights at all, so glare from the fog does not build up ahead
Show answer

Answer A: Low beams and fog lights, together with the four-way flashers

High beam light bounces back off the water droplets and makes seeing worse, while low beams, fog lights and flashers help you see and help others see you.

Source: dds.georgia.gov
What is the best practice when fog is thick enough to hide the road ahead?
1. Follow the tail lights of the vehicle ahead closely so you have a guide
2. Slow down before entering the fog, and if visibility is too poor, pull off into a rest area or truck stop until it improves
3. Pass slower vehicles quickly so you get clear of the fog bank
4. Stop in the traffic lane and wait there with the flashers on
Show answer

Answer B: Slow down before entering the fog, and if visibility is too poor, pull off into a rest area or truck stop until it improves

The safest choice in heavy fog is not to be driving in it, and if you are already in it your speed has to come down before your visibility does.

Source: dds.georgia.gov
You are drifting in the lane, yawning constantly and cannot remember the last few miles. What is the only reliable cure?
1. Strong coffee and an open window
2. Loud music and something to chew
3. Stopping in a safe place and sleeping
4. Driving faster so the trip ends sooner
Show answer

Answer C: Stopping in a safe place and sleeping

Those are classic drowsiness warning signs, and nothing except sleep repays the sleep the body is missing.

Source: dds.georgia.gov
Under the federal hours of service rules, how long may a property-carrying driver drive after 10 consecutive hours off duty?
1. Up to 8 hours, within a 12 hour window
2. Up to 10 hours, with no limit on the length of the window
3. Up to 14 hours, within a 16 hour window
4. Up to 11 hours, and only within a 14 hour window that starts when the driver comes on duty
Show answer

Answer D: Up to 11 hours, and only within a 14 hour window that starts when the driver comes on duty

The federal limit is 11 hours of driving after 10 consecutive hours off duty, and all of that driving has to fall inside a 14 hour window.

Source: fmcsa.dot.gov
The engine has overheated and you need to check the coolant. What is the safe procedure with a pressurized radiator cap?
1. Shut the engine off, let the system cool, protect your hands, turn the cap slowly to its first stop so pressure escapes, step back, then remove it
2. Remove the cap at once so the heat can escape faster
3. Pour cold water over the cap and open it straight away
4. Leave the engine running at high speed while you open the cap
Show answer

Answer A: Shut the engine off, let the system cool, protect your hands, turn the cap slowly to its first stop so pressure escapes, step back, then remove it

A hot pressurized system throws steam and boiling coolant out of the opening, so the pressure is released slowly and only after the engine has cooled.

Source: dds.georgia.gov
A fire has started in the vehicle. How should the extinguisher be used?
1. Spray into the top of the flames from close range
2. Stay as far back as the reach of the extinguisher allows, stand upwind, and aim at the base of the fire
3. Open the cargo doors first so the smoke can escape
4. Use water on the fire, whatever the burning material is
Show answer

Answer B: Stay as far back as the reach of the extinguisher allows, stand upwind, and aim at the base of the fire

Aiming at the base attacks what is actually burning, and staying upwind and well back protects the driver from heat, smoke and the flames themselves.

Source: dds.georgia.gov
What are the rules for using your turn signal before a turn or lane change?
1. Signal early, keep the signal on until the turn is finished, then cancel it
2. Signal at the moment you begin turning so other drivers are not confused too early
3. Signal only when another vehicle is close enough to be affected by your move
4. Signal briefly, then cancel it before the turn so the flashing does not distract others
Show answer

Answer A: Signal early, keep the signal on until the turn is finished, then cancel it

An early, continuous signal tells others what you plan to do; cancelling afterward keeps the signal from misleading them.

Source: oregon.gov
You are about to slow down sharply on a highway to make a turn into a narrow driveway. How can you warn the drivers behind you?
1. Turn on the high beams, which drivers behind will see reflected in their mirrors
2. Sound the horn continuously from the moment you slow until the turn is complete
3. Tap the brake pedal a few times so the brake lights flash before you slow down
4. Move to the center of the road so the drivers behind can pass on both sides
Show answer

Answer C: Tap the brake pedal a few times so the brake lights flash before you slow down

A few light taps flash the brake lights and give following drivers an early warning that you are about to slow or stop.

Source: oregon.gov
A driver behind you wants to pass and you can see that the road ahead is clear. What should you do?
1. Wave the driver past, because you can see farther ahead from the higher cab
2. Do not signal the other driver to pass; let that driver decide when it is safe
3. Flash your left turn signal to show the driver that the road ahead is clear
4. Move onto the shoulder and stop until the driver has passed you completely
Show answer

Answer B: Do not signal the other driver to pass; let that driver decide when it is safe

Directing other drivers can cause a crash if you misjudge the gap, so leave the decision to the driver who is passing.

Source: oregon.gov
You must drive well below the speed of surrounding traffic, for example when climbing a steep grade with a heavy load. What should you do?
1. Turn off all lights so drivers behind notice the vehicle only when they are close
2. Turn on the four-way flashers to warn following traffic, where state law allows it
3. Drive on the shoulder, because slow vehicles are not allowed in the traffic lanes
4. Use the horn every few seconds so the drivers behind know that you are slow
Show answer

Answer B: Turn on the four-way flashers to warn following traffic, where state law allows it

Flashers warn faster traffic that a slow-moving vehicle is ahead, which helps prevent rear-end crashes; some states restrict their use while moving, so check the local rule.

Source: oregon.gov
How do objects appear in a convex mirror compared with a flat mirror?
1. Larger and closer than they really are, while a narrower area is shown
2. Smaller and farther away than they really are, while a wider area is shown
3. Exactly the same size and distance, but upside down and reversed
4. Clearer at night and blurrier during the day, with the same field of view
Show answer

Answer B: Smaller and farther away than they really are, while a wider area is shown

A convex mirror shows a wider field but shrinks everything in it, so the driver must remember that vehicles are closer than they look.

Source: oregon.gov
An oncoming vehicle at night has bright headlights that are making it hard to see. What should you do?
1. Turn on your high beams so the other driver dims theirs and you can see again
2. Look toward the right edge of your lane and avoid looking directly at the lights
3. Close one eye until the vehicle passes so that eye stays adjusted to the dark
4. Slow to a crawl in the lane and look straight into the lights until they pass
Show answer

Answer B: Look toward the right edge of your lane and avoid looking directly at the lights

Looking at the right edge of the road keeps your eyes off the glare while you stay in your lane; glare can leave you nearly blind for several seconds.

Source: oregon.gov
What does it mean to overdrive your headlights at night?
1. Driving with the high beams on while another vehicle is within 500 feet of you
2. Leaving the headlights on during the day, which wears out the bulbs faster
3. Driving with the dashboard lights turned up so bright that the road looks dim
4. Driving so fast that you cannot stop within the distance lit by your headlights
Show answer

Answer D: Driving so fast that you cannot stop within the distance lit by your headlights

You must be able to stop inside the distance you can see; at night that distance is limited by the headlights, so speed must be lowered to match.

Source: oregon.gov
Where on the road are you most likely to find ice in cold weather?
1. On stretches that get direct sunlight, because melting snow refreezes there first
2. On bridges, overpasses and shaded stretches, which freeze before the rest of the road
3. In the middle of the travel lane, where tire heat drives moisture into the surface
4. On long straight sections, where the wind keeps the pavement colder than in curves
Show answer

Answer B: On bridges, overpasses and shaded stretches, which freeze before the rest of the road

Bridges and overpasses lose heat from above and below, and shaded areas get no sun, so they ice over first and stay icy longest.

Source: oregon.gov
The temperature is around freezing and the road looks wet. What is a practical way to tell whether it is icy?
1. Open the window and listen for the tires to squeal, which happens only on dry pavement
2. Brake hard once in traffic to see whether the vehicle slides on the surface
3. Check for ice building up on the mirrors, antenna or the front of the vehicle
4. Assume the road is dry, because ice always looks white and rough from the cab
Show answer

Answer C: Check for ice building up on the mirrors, antenna or the front of the vehicle

Ice that forms on the mirror, antenna or windshield is a warning that the road surface is freezing too, and black ice can look like a wet road.

Source: oregon.gov
When is a road surface usually most slippery during a rain shower?
1. Just after the rain starts, when water mixes with oil and dirt on the surface
2. Only after several hours of heavy rain, when the oil has been washed away
3. Just after the rain stops, when the sun begins drying the pavement
4. Only when the temperature is above 90 degrees and the rain evaporates quickly
Show answer

Answer A: Just after the rain starts, when water mixes with oil and dirt on the surface

The first rain lifts oil and dust into a slick film that has not yet been washed away, so the road is more slippery than it will be later.

Source: oregon.gov
Your vehicle begins to hydroplane on a wet road. What should you do?
1. Brake firmly and steer sharply toward the shoulder to get off the wet pavement as quickly as possible
2. Release the accelerator and push in the clutch so the wheels can turn freely and regain grip
3. Accelerate to push the tires through the water and back onto the road surface underneath
4. Apply the parking brake gently while keeping the accelerator steady so the vehicle stays straight
Show answer

Answer B: Release the accelerator and push in the clutch so the wheels can turn freely and regain grip

Hydroplaning tires are riding on water; slowing without braking lets them settle back onto the road and grip again.

Source: oregon.gov
Why should you never shift gears while crossing railroad tracks?
1. You could miss the gear or stall and be stuck on the tracks
2. The rails can damage the transmission if the gears are moving at the time
3. The train crew is required to stop if they see brake lights on the crossing
4. Shifting on the tracks sets off the crossing signals for approaching trains
Show answer

Answer A: You could miss the gear or stall and be stuck on the tracks

A stalled or coasting vehicle on the tracks has no way to clear quickly, so choose the gear before the crossing and do not shift until you are across.

Source: oregon.gov
Under federal rules, what is required of a commercial driver who wants to use a mobile phone while driving?
1. The phone may be held to the ear as long as the driver stays in the right lane and below the speed limit
2. The phone must be hands-free and started with no more than a single button press, and it must not be held
3. The driver may send text messages while stopped at a traffic light but not while the vehicle is moving
4. There are no federal limits at all; only state laws restrict phone use in commercial vehicles
Show answer

Answer B: The phone must be hands-free and started with no more than a single button press, and it must not be held

Federal rules ban texting and hand-held phone use while driving a commercial vehicle; reaching for, holding or dialing a phone is a violation.

Source: ecfr.gov
A driver is tailgating you, honking and making gestures. What is the best response?
1. Do not make eye contact, ignore the gestures and give the driver room to get past
2. Slow down suddenly several times so the driver learns to keep a safe following distance
3. Speed up so the driver has to work much harder to keep up with you
4. Return the gestures so the driver knows that you are not intimidated
Show answer

Answer A: Do not make eye contact, ignore the gestures and give the driver room to get past

Engaging an aggressive driver only escalates the situation; the safest move is to stay calm, avoid eye contact and let the driver get by.

Source: oregon.gov
Under federal rules, what happens to a commercial driver found with any detectable amount of alcohol while operating a commercial vehicle?
1. The driver receives a warning and may continue driving after one hour of rest
2. Nothing, as long as the blood alcohol concentration is below 0.04 percent
3. The driver must drink water and retake the roadside test after 30 minutes
4. The driver is placed out of service for 24 hours
Show answer

Answer D: The driver is placed out of service for 24 hours

Any measurable alcohol takes a commercial driver off the road for 24 hours, and a concentration of 0.04 percent or more brings a disqualification.

Source: ecfr.gov
At what time of day do drowsy driving crashes occur most often?
1. Between midnight and 6 a.m.
2. Between noon and 2 p.m.
3. Between 7 a.m. and 9 a.m.
4. Between 5 p.m. and 7 p.m.
Show answer

Answer A: Between midnight and 6 a.m.

The body clock makes people sleepiest in the early morning hours, which is when most fatigue-related crashes happen.

Source: oregon.gov
An empty van trailer cleared a low overpass on the way in, but on the way back it is loaded. Which statement is true?
1. A loaded van rides higher than an empty one, so it needs more clearance than when empty
2. Load has no effect on trailer height, so the same overpass is always safe in both directions
3. An empty van rides higher than a loaded one, so it needs more clearance than when loaded
4. Only the posted sign matters, so the load on the vehicle never has to be considered
Show answer

Answer C: An empty van rides higher than a loaded one, so it needs more clearance than when loaded

Springs compress under load, so an empty trailer is taller; the unloaded trip is the one that can catch a low overhead.

Source: oregon.gov
Study tip. When two answers both seem legal, pick the one that is safer for everyone on the road. That is how most tests are written.
An oncoming vehicle drifts across the center line into your lane. What is usually the safest move?
1. Steer to the left into the oncoming lane, because the other driver will correct
2. Stop in your lane and flash the headlights so the other driver sees you
3. Steer to the right, toward the shoulder if necessary
4. Speed up to get past the other vehicle before it reaches you
Show answer

Answer C: Steer to the right, toward the shoulder if necessary

Moving right keeps you away from the drifting vehicle and off the oncoming side; the other driver may swerve back and hit you if you go left.

Source: oregon.gov
At 55 mph, about how far does a vehicle travel during a typical 3/4 second perception time plus 3/4 second reaction time, before the brakes even begin to work?
1. About 20 feet
2. About 300 feet
3. About 120 feet
4. About 600 feet
Show answer

Answer C: About 120 feet

Each 3/4 second at 55 mph covers about 60 feet, so perception and reaction together use up roughly 120 feet before braking starts.

Source: oregon.gov
A fire starts in the cargo area of a van trailer. Why should you keep the doors closed until firefighters arrive?
1. The cargo could fall out and block the road for emergency vehicles
2. The insurance company must inspect the load before the doors are opened
3. The smoke would damage the door seals and make the trailer unusable
4. Opening the doors lets in air that feeds the fire
Show answer

Answer D: Opening the doors lets in air that feeds the fire

A fire in a closed van is starved of oxygen; opening the doors gives it the air it needs to flare up.

Source: oregon.gov
At highway speed, looking 12 to 15 seconds ahead means looking about how far down the road?
1. About one city block, which is the figure used at low city speeds
2. About a quarter of a mile
3. About one full mile, which is roughly the reach of a high beam
4. About fifty yards, which is close to two vehicle lengths ahead
Show answer

Answer B: About a quarter of a mile

Twelve to fifteen seconds of travel is roughly a quarter of a mile at highway speed, while the same amount of time is about one block in slow city traffic.
Why does the commercial driver manual tell you to look far down the road instead of only at the vehicle ahead?
1. So you can hold a steady engine speed and save fuel on every trip
2. So you no longer need to check the mirrors while moving with traffic
3. So you can safely follow more closely than the seconds rule requires
4. So you can adjust smoothly instead of braking hard at the last moment
Show answer

Answer D: So you can adjust smoothly instead of braking hard at the last moment

A heavy vehicle cannot react quickly, so early information lets you slow gradually rather than make a sudden stop or swerve.
You are on a freeway and see brake lights come on in several vehicles far ahead of you. What should you do?
1. Ease off the accelerator and get ready to slow down
2. Hold your speed until the vehicle directly ahead of you slows down
3. Change lanes at once without waiting to see what the traffic does
4. Sound the horn to warn the drivers who are traveling behind you
Show answer

Answer A: Ease off the accelerator and get ready to slow down

Brake lights well ahead are an early warning that traffic is slowing, and acting on them gives a heavy vehicle the room it needs.
Part of looking well ahead is planning an out. What does that mean?
1. Choosing your exit ramp before you enter a busy stretch of freeway
2. Keeping an escape path in mind in case traffic stops suddenly
3. Deciding in advance which single lane you will use for the whole trip
4. Leaving the road at the first rest area whenever traffic becomes heavy
Show answer

Answer B: Keeping an escape path in mind in case traffic stops suddenly

Because a heavy vehicle often cannot stop in time, good drivers continuously note where they could steer if the space ahead closes.
In dense city traffic you cannot see 12 seconds ahead because other vehicles block the view. What is the best response?
1. Slow down and open up more space in front of you
2. Move into the lane that has the fewest vehicles and hold your speed
3. Follow the vehicle ahead closely so you can copy what that driver does
4. Watch only the vehicle directly ahead and ignore the traffic beyond it
Show answer

Answer A: Slow down and open up more space in front of you

When you cannot see far enough ahead, extra following distance buys back the reaction time that the blocked view has taken away.
Which situations call for a mirror check in a commercial vehicle?
1. Every lane change, turn, merge and tight maneuver
2. Only a lane change that is made on a multilane highway after dark
3. Only when a warning light appears on the instrument panel
4. Only when another driver sounds a horn somewhere behind you
Show answer

Answer A: Every lane change, turn, merge and tight maneuver

Mirrors must be checked regularly and always before, during and after any movement that changes the path of the vehicle.
Why should the mirrors be checked repeatedly while you make a tight turn?
1. To confirm that the trailer marker lamps stay lit throughout the turn
2. To read the tire pressure gauges fitted to the trailer axles
3. To watch the rear of the vehicle clear other vehicles and objects
4. To make sure that following drivers have turned their headlights on
Show answer

Answer C: To watch the rear of the vehicle clear other vehicles and objects

In a long vehicle the rear wheels cut inside the path of the front wheels, so only the mirrors show whether the rear is clearing curbs, poles and other vehicles.
You have just passed another vehicle on a two lane road. What tells you it is safe to return to your lane?
1. The driver you passed flashes the headlights at you two times
2. You can see the whole front of that vehicle in your right mirror
3. Ten seconds have gone by since you moved out to begin the pass
4. You can no longer see that vehicle in either of your side mirrors
Show answer

Answer B: You can see the whole front of that vehicle in your right mirror

Seeing the entire front of the vehicle you passed in your mirror proves you are far enough ahead to move back over without cutting the driver off.
You are pulling away from the curb after a delivery. Why is a mirror check needed first?
1. The mirrors are the only way to confirm the parking brake has released
2. A cyclist or a vehicle may be coming up alongside you
3. A mirror check is the only way to confirm that the trailer doors are shut
4. The mirrors will show whether the tires have lost pressure while parked
Show answer

Answer B: A cyclist or a vehicle may be coming up alongside you

Traffic and cyclists can arrive alongside a parked vehicle at any moment, so the mirrors must be checked immediately before pulling out.
Regular mirror checks during a long trip can reveal which developing problem?
1. A drop in the reading of the engine oil pressure gauge
2. A slow loss of pressure in the air brake supply tank
3. A fault inside the antilock brake system control module
4. Smoke coming from a tire or from a wheel
Show answer

Answer D: Smoke coming from a tire or from a wheel

Overheating tires, wheel bearings and brakes usually show as smoke long before anything appears on the dash, and mirrors are where a driver sees it.
You have finished a lane change in a vehicle whose turn signal does not cancel by itself. What must you do?
1. Leave the signal on until the next turn so drivers behind stay alert
2. Switch on the four-way flashers so that the signal is easier to see
3. Tap the brake pedal twice so that the signal resets on its own
4. Turn the signal off yourself
Show answer

Answer D: Turn the signal off yourself

A signal left running tells other drivers you are about to move again, and they may act on that false information.
You need to pull off onto the shoulder because of a problem with the load. How should you communicate that to other drivers?
1. Sound the horn several times as you drift toward the shoulder
2. Switch on the high beams so drivers behind can see the vehicle
3. Wait until you are fully stopped before giving any signal at all
4. Signal the move, then switch on the four-way flashers once stopped
Show answer

Answer D: Signal the move, then switch on the four-way flashers once stopped

Other drivers need a signal before you leave the lane and a clear warning once the vehicle is stopped near the traffic lanes.
When should the horn of a commercial vehicle be used?
1. Whenever a driver behind you is following far too closely
2. To let a driver who has cut you off know that you are annoyed
3. Only when it is needed to avoid a crash
4. As a greeting to other drivers whenever you pass them on a highway
Show answer

Answer C: Only when it is needed to avoid a crash

An air horn is loud enough to startle other road users, so it is a warning device rather than a way to comment on other drivers.
Besides the hours when the law requires them, when should headlights be switched on?
1. Any time visibility is poor, such as in rain, fog or at dusk
2. Only once full darkness has fallen and the street lights come on
3. Only when the other drivers around you have already turned theirs on
4. Only when the windshield wipers are running at their fastest setting
Show answer

Answer A: Any time visibility is poor, such as in rain, fog or at dusk

Headlights are used to be seen as much as to see, so they belong on whenever light or weather makes the vehicle harder to spot.
You have stopped and a pedestrian is waiting to cross in front of your truck. Why should you not wave the person across?
1. A hand signal given from a truck cab is not legal in most situations
2. The pedestrian would then be responsible for any crash that follows
3. Another driver may not stop, and your wave sends the person into danger
4. Waving takes a hand off the wheel, which federal rules do not allow
Show answer

Answer C: Another driver may not stop, and your wave sends the person into danger

You cannot control what drivers in the other lanes will do, so you should not invite a pedestrian into a lane you do not command.
Why should you avoid using your lights to tell a following driver that it is safe to pass you?
1. A light signal like that is treated as unlawful in every state
2. You may misjudge the gap and the driver will act on your signal
3. The following driver cannot see any light signal from behind a trailer
4. Your brake lights would then not work again for several seconds
Show answer

Answer B: You may misjudge the gap and the driver will act on your signal

The manual warns against signaling others to pass, because the responsibility for a head-on crash then rests on a judgment you could easily get wrong.
You drive a 40 foot straight truck at 50 miles per hour in good conditions. What following distance does the rule of thumb call for?
1. 5 seconds
2. 3 seconds
3. 4 seconds
4. 7 seconds
Show answer

Answer A: 5 seconds

One second for every 10 feet of vehicle length gives 4 seconds, and one extra second is added for speeds above 40 miles per hour.
When should a driver add space beyond the basic following distance rule?
1. Only when the vehicle is carrying placarded hazardous materials
2. Only when the vehicle behind you is another heavy commercial truck
3. Only where the posted speed limit is above 65 miles per hour
4. On slippery roads and whenever visibility is poor
Show answer

Answer D: On slippery roads and whenever visibility is poor

The seconds rule is a minimum for good conditions, so rain, snow, darkness and heavy traffic all call for more space than that.
A car that passed you on the right slows and stays alongside your trailer. What is the best response?
1. Speed up so the pass ends sooner and the car drops behind you
2. Move to the left edge of your lane and sound the horn twice
3. Signal a right lane change so that the driver understands to move over
4. Ease off the accelerator so the car can move clear
Show answer

Answer D: Ease off the accelerator so the car can move clear

A vehicle sitting beside a trailer is in a blind area and has nowhere to go if you need the lane, so the safest fix is to let it get ahead or behind.
An overpass you have driven under before now has a fresh layer of pavement on the road below it. Why does that matter?
1. Fresh pavement stays more slippery than the old surface for several weeks
2. The new layer raises the road and reduces the clearance
3. The new surface adds weight to the bridge and lowers its rated capacity
4. Repaving means the posted height sign has already been raised to match
Show answer

Answer B: The new layer raises the road and reduces the clearance

Repaving lifts the road surface, so the real clearance under a structure can be less than the height posted on it.
You are backing into a yard where electrical wires cross overhead. What is the main concern?
1. The wires can interfere with the radio and the electronic logging device
2. Wires above a yard are always high enough for any legal vehicle height
3. The wires may hang lower than the top of your vehicle
4. Backing under wires is only a problem when the trailer is fully empty
Show answer

Answer C: The wires may hang lower than the top of your vehicle

Overhead space has to be checked like any other space around the vehicle, because wires and cables are often lower than they look from the cab.
You are entering a freeway from a short ramp with a fully loaded trailer. What should you do?
1. Begin building speed early and wait for a large gap
2. Stop at the end of the ramp and wait for traffic to open a lane for you
3. Enter at low speed and gain the rest of the speed in the traffic lane
4. Take the nearest gap and expect the traffic behind you to slow down
Show answer

Answer A: Begin building speed early and wait for a large gap

A loaded vehicle accelerates slowly, so it needs both a running start and a much larger gap than a car would use.
You are stopped in a line of traffic behind a car. How much space should you leave in front of you?
1. Just enough that no other driver is able to move in ahead of you
2. About one vehicle length for every 10 miles per hour of the speed limit
3. Enough to see where the rear tires of that car meet the road
4. As little as possible so that the line of traffic takes up less road
Show answer

Answer C: Enough to see where the rear tires of that car meet the road

That amount of space lets you pull around the vehicle ahead if it stalls and absorbs some of the shock if you are struck from behind.
Around a tractor-trailer, where are the blind areas that other drivers most often sit in unseen?
1. Along the right side and directly behind the trailer
2. Directly ahead of the cab and along the left front fender
3. Above the cab and along the top edges of the trailer roof
4. Only in the space between the tractor and the trailer wheels
Show answer

Answer A: Along the right side and directly behind the trailer

The blind areas to the right of the cab and behind the trailer are the largest, which is why other drivers should never linger there.
Most rollovers of loaded trucks on exit and entrance ramps happen for which reason?
1. The ramp surface was banked the wrong way for a heavy vehicle
2. The ramp was taken faster than the load could tolerate
3. The trailer brakes were applied before the tractor brakes were
4. The driver selected a gear that was too low for the curve ahead
Show answer

Answer B: The ramp was taken faster than the load could tolerate

A posted ramp speed is set for cars, and a loaded trailer with a high center of gravity can roll at a speed a car would take easily.
How does a load carried high in the trailer affect safe speed through a curve?
1. It has no effect as long as the load is within the legal weight limit
2. It raises the rollover risk, so the speed must be lower
3. It lowers the center of gravity and makes the vehicle more stable
4. It matters only when the trailer is loaded to less than half capacity
Show answer

Answer B: It raises the rollover risk, so the speed must be lower

A high center of gravity lets the vehicle tip long before the tires lose their grip, so height of the load directly limits curve speed.
Why is driving much slower than the rest of the traffic dangerous?
1. A slow vehicle burns more fuel than one running at the speed limit
2. Other drivers must keep passing you, which creates conflicts
3. Slow driving overheats the engine and the whole exhaust system
4. Running slowly wears the tires unevenly across the width of the tread
Show answer

Answer B: Other drivers must keep passing you, which creates conflicts

Traffic that has to work its way around you produces lane changes and closing speeds, which is why a large speed difference is itself a hazard.
Study tip. One test a day for a week beats seven tests in one evening: spaced practice is what makes rules stick.
Why does extra weight make a long downgrade more dangerous even when the brakes are in good order?
1. Extra weight cuts the air pressure that reaches the brake chambers
2. Gravity adds to the momentum and the brakes heat up faster
3. Extra weight shifts the load forward and lifts the drive axle tires
4. Extra weight lowers engine speed so the retarder cannot be engaged
Show answer

Answer B: Gravity adds to the momentum and the brakes heat up faster

The heavier the vehicle, the more energy the brakes must turn into heat, and heat is exactly what makes brakes fade on a long descent.
What is generally the safest speed in dense but freely moving highway traffic?
1. Ten miles per hour below the traffic so you keep more space ahead
2. The maximum posted limit no matter what the other traffic is doing
3. Whatever speed lets you stay in the left lane and avoid merging traffic
4. The speed of the traffic around you, up to the posted limit
Show answer

Answer D: The speed of the traffic around you, up to the posted limit

Crashes rise with the difference between your speed and the traffic around you, so moving with the flow within the legal limit is safest.
You have chosen 40 miles per hour as your safe speed for a downgrade. How should the brakes be used?
1. Brake firmly to about 35, release, and repeat at 40
2. Hold light steady pressure so that the speed never reaches 40 at all
3. Brake down to about 20 each time so you have a larger safety margin
4. Wait until the speed has reached about 55 and then brake back to 40
Show answer

Answer A: Brake firmly to about 35, release, and repeat at 40

Proper technique is firm application to about 5 miles per hour below the safe speed, then full release so the brakes cool before the next application.
Your brakes are starting to fade on a mountain downgrade and a sign shows an escape ramp one mile ahead. What should you do?
1. Continue down and use the ramp only if the brakes fail completely
2. Plan to use the ramp instead of trying to reach the bottom
3. Shift into neutral so the wheels turn freely and the brakes can cool
4. Pump the brake pedal quickly to build back the pressure you have lost
Show answer

Answer B: Plan to use the ramp instead of trying to reach the bottom

Fading brakes on a grade only get worse, and the ramp exists precisely so a driver does not have to gamble on the rest of the descent.
How does a typical escape ramp stop a runaway vehicle?
1. With a sharp curve at the end that scrubs off the remaining speed
2. With a bed of loose gravel or sand, often on an upgrade
3. With an automatic barrier that lowers once a vehicle enters the ramp
4. With a steel grid set into the surface that grips and holds the tires
Show answer

Answer B: With a bed of loose gravel or sand, often on an upgrade

Escape ramps use deep loose material, usually combined with a rising grade, so the vehicle is slowed gradually instead of being stopped by impact.
A sign before a long descent shows 6 percent. What does that number tell you?
1. How steep the grade ahead is
2. How many miles of curves lie before the bottom of the hill
3. The share of that roadway that has been resurfaced recently
4. The maximum load that a vehicle may carry down that section
Show answer

Answer A: How steep the grade ahead is

Percent grade is the drop in feet for every hundred feet of road, so the higher the number the faster speed will build and the lower the gear you need.
What does mountain driving demand that flat country driving does not?
1. Higher tire pressure at the top of every long climb or descent
2. The highest available gear at all times to reduce engine wear
3. Closer following so that other drivers cannot merge in between
4. Lower gears and constant allowance for gravity
Show answer

Answer D: Lower gears and constant allowance for gravity

In the mountains gravity works for you on the climb and against you on the descent, so gear selection and speed control matter far more than on level road.
What should be done before a night trip to get the most from your headlights?
1. Aim the headlights slightly higher than the daytime setting
2. Turn the instrument panel lights up to their brightest setting
3. Clean the windshield, the mirrors and the lights
4. Fit a tinted film to the windshield to soften the oncoming glare
Show answer

Answer C: Clean the windshield, the mirrors and the lights

Dirt on glass and lenses cuts both the light you throw down the road and the light that reaches your eyes, so cleaning is the cheapest night safety measure there is.
Why is it harder to judge speed and distance at night?
1. Headlights make other vehicles look closer than they really are
2. The eyes react more quickly at night and misread the road ahead
3. You see much less detail and have fewer reference points
4. Cool night air carries sound farther and confuses the driver
Show answer

Answer C: You see much less detail and have fewer reference points

Darkness removes the visual references that the brain uses to estimate distance and closing speed, so drivers routinely misjudge both.
Which road users are hardest to see at night?
1. Vehicles that are traveling with only their low beams switched on
2. Vehicles stopped on the shoulder with their four-way flashers running
3. Pedestrians and cyclists in dark clothing
4. Motorcycles that are being ridden with the headlight switched on
Show answer

Answer C: Pedestrians and cyclists in dark clothing

People on foot or on a bicycle carry no lights of their own in many cases, so they appear only when the headlights reach them.
Why should high beams not be used in fog?
1. The light reflects back off the droplets and blinds you
2. High beams draw so much current that the batteries can run flat
3. The extra heat from a high beam can crack a cold headlight lens
4. High beams may only be used on roads that have no street lighting
Show answer

Answer A: The light reflects back off the droplets and blinds you

Fog is made of water droplets that scatter light straight back at the driver, so a stronger beam makes the wall of glare worse rather than better.
Where should a driver expect fog to form first?
1. On high ridges where the wind is strongest during the night
2. On long straight stretches that face directly into the sunset
3. On freshly paved sections that hold their heat after sunset
4. In low ground, near water and in valleys
Show answer

Answer D: In low ground, near water and in valleys

Cool moist air settles in low places, so fog patches appear in hollows, river valleys and near lakes before they appear anywhere else.
Why is a leak in the exhaust system especially dangerous in cold weather?
1. Carbon monoxide can build up inside a closed cab
2. Cold air makes exhaust gas burn the paint off the frame rails
3. A leak lets cold air into the engine and stops it warming up
4. The leak lowers exhaust pressure and shuts down the cab heater
Show answer

Answer A: Carbon monoxide can build up inside a closed cab

In winter the windows are shut and the heater is running, so exhaust gas that escapes early can reach the driver and cause drowsiness or worse.
A hard frost has left your vehicle covered in ice. What must be cleared before you drive?
1. Only the part of the windshield that the wipers actually sweep clear
2. Only the windshield, because the mirrors will clear as you drive along
3. Only the headlights, because airflow will remove the rest of the ice
4. The windshield, mirrors, lights and reflectors
Show answer

Answer D: The windshield, mirrors, lights and reflectors

You must be able to see out and other drivers must be able to see your lights and reflectors, so all of those surfaces have to be cleared.
Besides slowing down, which technique most reduces the risk of a skid on a snow covered road?
1. Keep the vehicle in the highest gear that the engine will pull
2. Make every steering, braking and speed change gradual
3. Use the trailer brakes alone whenever you need to slow the vehicle
4. Steer with short, quick corrections to keep the vehicle running straight
Show answer

Answer B: Make every steering, braking and speed change gradual

Traction is limited on snow, and sudden inputs demand more grip than the surface can supply, so smoothness is what keeps the tires attached to the road.
Why should a driver avoid stopping partway up a snow covered hill?
1. The parking brake can freeze on and lock the drive wheels solid
2. Stopping on a grade in snow overheats the clutch and the driveline
3. The load will shift to the rear and lift the steering axle tires
4. You may not get moving again and could slide backwards
Show answer

Answer D: You may not get moving again and could slide backwards

On a slippery grade the drive wheels may simply spin when you try to restart, leaving the vehicle stuck across the road or sliding back down it.
Which winter preparation matters most for keeping the road in view?
1. A fresh set of tire chains stowed behind the driver seat
2. A block heater fitted to the engine before the first hard frost
3. An extra pair of mirrors mounted on the front of the hood
4. Working wipers, washer fluid and a working defroster
Show answer

Answer D: Working wipers, washer fluid and a working defroster

Slush and road spray coat the windshield within minutes in winter, so wipers, washer fluid and the defroster are what keep any view at all.
Which vehicle condition makes hydroplaning more likely?
1. A load that is placed toward the rear of the trailer
2. Brake linings that have recently been replaced
3. Tires that are worn or underinflated
4. A drive axle that is fitted with new radial tires
Show answer

Answer C: Tires that are worn or underinflated

Tread depth and correct pressure are what let a tire push water aside, so worn or soft tires lift onto the water film at lower speeds.
Why do worn tires lose grip so quickly on a wet road?
1. Worn tires run hotter and the rubber goes harder in the rain
2. Worn tires carry less weight so they press less firmly on the road
3. Worn tires make the antilock brake system release the brakes early
4. Shallow tread cannot move water out from under the tire
Show answer

Answer D: Shallow tread cannot move water out from under the tire

The grooves in a tire exist to channel water away so the rubber can touch the road, and a worn tire has lost that capacity.
Which vehicle is most likely to be pushed around by a strong crosswind?
1. A loaded flatbed that is carrying steel coils
2. An empty van trailer
3. A loaded tank trailer with a full load of fuel
4. A dump truck carrying a full load of wet gravel
Show answer

Answer B: An empty van trailer

A large flat side with very little weight behind it gives the wind the most surface and the least resistance, which is the empty van trailer.
You are about to cross a long, high bridge with a light load in gusty wind. What should you do?
1. Speed up so that you spend less time exposed out on the bridge
2. Move into the lane nearest the upwind railing of the bridge deck
3. Slow down and be ready for a sudden push
4. Hold the wheel loosely so a gust cannot twist it out of your hands
Show answer

Answer C: Slow down and be ready for a sudden push

Wind is strongest where a bridge leaves the shelter of the land, and lower speed gives you time to correct when the first gust hits.
Under federal rules, which commercial vehicles must stop at every railroad crossing before proceeding?
1. Any vehicle with a gross combination weight above 26,001 pounds
2. Any vehicle that is towing a trailer more than 40 feet in length
3. Every commercial vehicle, whatever the cargo it happens to carry
4. Passenger buses and placarded hazardous materials vehicles
Show answer

Answer D: Passenger buses and placarded hazardous materials vehicles

Buses carrying passengers and vehicles required to display hazardous materials placards must stop at crossings, while other commercial vehicles slow and check.

Source: ecfr.gov
Your vehicle stalls on a railroad crossing and a train is coming. What should you do?
1. Stay in the cab and keep trying to restart the engine until it fires
2. Stand beside the vehicle and wave your arms to warn the train crew
3. Get out at once and move toward the train, well off to one side
4. Run away from the tracks in the same direction the train is heading
Show answer

Answer C: Get out at once and move toward the train, well off to one side

Leave the vehicle immediately and move at an angle toward the oncoming train, so that wreckage thrown forward by the impact travels away from you.
Which vehicles are most likely to get hung up on a raised railroad crossing?
1. Low-slung units such as car carriers and lowboys
2. Empty dump trucks with the body raised for cleaning
3. Tank trailers with a low center of gravity and a full load
4. Tractors that are pulling two short trailers instead of one
Show answer

Answer A: Low-slung units such as car carriers and lowboys

Vehicles with low ground clearance or a long wheelbase can bottom out on a humped crossing and become stuck on the tracks.
Why should the radio, the fan and other noisy equipment be switched off during a required stop at a railroad crossing?
1. So that the crossing signals are not disturbed by electrical noise
2. So that the engine does not stall while the vehicle is standing still
3. So that an approaching train can be heard
4. So that any passengers can hear an announcement from the driver
Show answer

Answer C: So that an approaching train can be heard

The rules require the driver to look and listen along the track, and on a double track crossing a passing train can hide a second one, so hearing matters as much as seeing.
You are not certain that your loaded vehicle will clear a low overpass. What should you do?
1. Take another route rather than risk it
2. Move to the middle of the road where the arch is highest and creep under
3. Let some air out of the tires so the vehicle sits an inch or two lower
4. Speed up slightly so the suspension compresses as you pass under it
Show answer

Answer A: Take another route rather than risk it

There is no safe way to guess at a clearance, and striking a bridge endangers everyone on and under it, so the only correct choice is a different route.
In hazard perception, what counts as a hazard?
1. Only a vehicle that has already started to move into your lane
2. Only a defect in the road surface that could damage the vehicle
3. Any road user or condition that could become a danger
4. Only a situation that forces you to make an emergency stop
Show answer

Answer C: Any road user or condition that could become a danger

A hazard is anything with the potential to create danger, which is why drivers are taught to spot them early rather than react to emergencies.
A car ahead of you keeps drifting within its lane and moving unevenly. What should you assume?
1. The car most likely has a tire that is slowly losing pressure
2. The driver is deliberately trying to make you pass on the right
3. The driver may be distracted, lost or impaired
4. The road is crowned and every vehicle there drifts in the same way
Show answer

Answer C: The driver may be distracted, lost or impaired

Unsteady lane keeping is a classic clue to a driver who is not in full control, so the safe response is to keep back and give plenty of room.
Which clues warn you that a parked car may pull out or open a door?
1. Exhaust smoke, turned front wheels, a person in the seat
2. Fresh mud on the wheels and a cold engine hood at the front
3. An expired parking meter and a permit displayed in the window
4. Open windows and a vehicle that is parked close to the corner
Show answer

Answer A: Exhaust smoke, turned front wheels, a person in the seat

Signs of life in a parked vehicle, such as a running engine, turned wheels or an occupant, mean it may move or open a door into your path.
A delivery van is stopped in the right lane ahead with its flashers on. What should you expect?
1. The van will reverse suddenly along the lane toward your vehicle
2. The van will pull into the left lane without giving any signal
3. Someone may step into your lane from in front of it
4. The lane beyond the van will be blocked by a second parked vehicle
Show answer

Answer C: Someone may step into your lane from in front of it

A stopped delivery vehicle hides the space in front of it, and that is exactly where a person carrying a package is likely to walk out.
Study tip. Before test day, check on the official agency website which documents and fees you need to bring.
The car in the next lane still has snow covering most of its windows. What should you assume?
1. That driver will keep to a low speed until the windows are clear
2. That the car has been abandoned and is being towed by another
3. That driver cannot see you and may move into your lane
4. That the driver has already checked the mirrors before setting off
Show answer

Answer C: That driver cannot see you and may move into your lane

A driver whose view is blocked cannot see the vehicles around, so you should assume you are invisible and stay out of that vehicle path.
You are driving past a park where children are playing close to the curb. What is the correct assumption?
1. A child may run into the street without looking
2. Children in a group will always stay together on the sidewalk
3. An adult nearby will always stop a child before the curb line
4. Children will hear a large engine and keep clear of the roadway
Show answer

Answer A: A child may run into the street without looking

Children act on impulse and do not judge traffic well, so a driver has to expect one to enter the road and slow down in advance.
What does safe practice require of a commercial driver who wants to eat, drink or read a delivery note?
1. Do it only while the vehicle is moving slowly in heavy traffic
2. Handle it before or after driving, not while moving
3. Do it only on a straight road where there is no other traffic
4. Do it only when the cruise control is holding a steady speed
Show answer

Answer B: Handle it before or after driving, not while moving

Anything that takes hands, eyes or attention away from the task belongs outside the driving time, not inside it.
You need to check your route on a navigation device. What is the correct approach?
1. Enter the address while you are stopped at a red light in traffic
2. Have a helper read the screen out to you at highway speed
3. Glance at the screen only when the road ahead is straight and clear
4. Set it before the trip or after you have parked
Show answer

Answer D: Set it before the trip or after you have parked

Route programming is planning work, and it belongs to the time before the wheels turn or after the vehicle is safely parked off the roadway.
Taking your eyes off the road for about five seconds at highway speed means traveling roughly how far unseen?
1. About the length of a football field
2. About the length of one tractor-trailer
3. About the width of a four lane highway
4. About the length of a city bus stop zone
Show answer

Answer A: About the length of a football field

At highway speed a five second glance away covers roughly 100 yards, which is far more road than any driver can afford to travel blind.

Source: fmcsa.dot.gov
Does the federal texting ban apply to a company dispatching device mounted in the cab?
1. No, the rule reaches only personal cell phones brought into the cab
2. Yes, entering or reading text on it while driving is banned
3. No, as long as the device is fixed to the dashboard or the console
4. Only when the vehicle is carrying placarded hazardous materials
Show answer

Answer B: Yes, entering or reading text on it while driving is banned

The rule is written around the act of reading or entering text on any electronic device, not around who owns the device.

Source: ecfr.gov
You drop your phone on the floor of the cab while driving. What do federal rules require?
1. Leave it, because reaching for it while driving is banned
2. Retrieve it quickly while keeping one hand on the steering wheel
3. Retrieve it only if you can do so without changing lanes at all
4. Retrieve it only after you have switched on your four-way flashers
Show answer

Answer A: Leave it, because reaching for it while driving is banned

Federal rules forbid reaching for a mobile device in any way that takes the driver out of a seated, belted driving position.

Source: ecfr.gov
May a commercial driver use a hand-held phone while stopped at a red light?
1. Yes, because the vehicle is not actually moving at that moment
2. No, a stop in traffic still counts as driving
3. Yes, as long as the call is finished within about one minute
4. Yes, provided that the parking brake has been set beforehand
Show answer

Answer B: No, a stop in traffic still counts as driving

Hand-held use is allowed only when the vehicle has been moved to the side of or off the highway and halted where it can safely remain stopped.

Source: ecfr.gov
What can repeated violations of the federal phone and texting rules cost a commercial driver?
1. A written warning placed in the carrier safety record only
2. A requirement to sit the general knowledge test a second time
3. A ban on driving at night for the following twelve months
4. Disqualification of the commercial driver license
Show answer

Answer D: Disqualification of the commercial driver license

Multiple convictions for using a hand-held phone or texting while driving a commercial vehicle lead to disqualification, on top of fines for driver and carrier.

Source: ecfr.gov
Why must the driver of a large vehicle keep it centered in its lane?
1. A centered vehicle wears its tires more evenly across the tread
2. The vehicle needs the full width of the lane
3. Centering keeps the trailer wheels off the reflective lane markers
4. It keeps the exhaust away from the vehicles in the next lane over
Show answer

Answer B: The vehicle needs the full width of the lane

A commercial vehicle is close to lane width already, so any drift takes part of the vehicle into the next lane or onto the shoulder.
On a multilane highway, which lane should a heavy vehicle normally use?
1. The right lane, except to pass or where signs direct otherwise
2. The middle lane at all times so traffic can pass on either side
3. The left lane, because it usually has the smoothest road surface
4. Whichever lane has the least traffic entering and leaving the road
Show answer

Answer A: The right lane, except to pass or where signs direct otherwise

Keeping right leaves the faster lanes free and reduces the number of vehicles that have to move around a slower, heavier vehicle.
What is the basic rule about backing a large vehicle?
1. Back only in daylight and only when the road surface is dry
2. Avoid backing whenever there is another way
3. Back only after you have sounded the horn three separate times
4. Back only in the highest gear that the transmission will take
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Answer B: Avoid backing whenever there is another way

Backing is dangerous because you cannot see everything behind you, so the manual tells drivers to plan routes and parking that avoid it.
You are backing with a helper guiding you and the helper drops out of sight in your mirror. What should you do?
1. Keep going slowly and expect the helper to come back into view
2. Stop until you can see the helper again
3. Sound the horn once and continue backing at the same slow speed
4. Set the parking brake and finish the maneuver without any help
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Answer B: Stop until you can see the helper again

If you cannot see the helper you cannot receive a signal to stop, so the only safe action is to halt until visual contact is restored.
How much sleep does a typical adult driver need each day to stay properly alert?
1. Three to four hours
2. Five to six hours
3. Ten to eleven hours
4. Seven to eight hours
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Answer D: Seven to eight hours

Most adults need seven to eight hours of sleep in every 24 hours, and a driver who regularly gets less builds up a debt that shows up behind the wheel.
A driver snores heavily, stops breathing briefly during the night and is tired all day despite long hours in bed. What should be suspected?
1. A poor diet with too little protein at the evening meal
2. Sleep apnea
3. Simple overwork that a single weekend at home will clear
4. A reaction to the vibration of driving over long distances
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Answer B: Sleep apnea

Sleep apnea repeatedly interrupts breathing during sleep, so the driver never gets true rest and stays dangerously drowsy during the day.
Under the federal hours of service rules, when must a property-carrying driver take a 30 minute break?
1. After 4 cumulative hours of driving time on any single day
2. After 6 hours counted from the moment the driver comes on duty
3. After 8 cumulative hours of driving time
4. After 10 cumulative hours of combined driving and loading work
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Answer C: After 8 cumulative hours of driving time

Driving is not allowed after 8 cumulative hours of driving time without at least a 30 consecutive minute interruption of driving.

Source: ecfr.gov
A carrier operates commercial vehicles every day of the week. What weekly on-duty limit applies to its drivers?
1. 70 hours in 8 consecutive days
2. 50 hours in 6 consecutive days
3. 60 hours in 8 consecutive days
4. 80 hours in 9 consecutive days
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Answer A: 70 hours in 8 consecutive days

The limit is 60 hours in 7 consecutive days for a carrier that does not run every day, and 70 hours in 8 consecutive days for one that does.

Source: ecfr.gov
How can a driver restart the 60 or 70 hour on-duty limit?
1. Take any 24 hours off duty spread over two calendar days
2. Take 34 or more consecutive hours off duty
3. Take two separate rest periods of 10 hours in the same week
4. Take 48 consecutive hours off duty at the home terminal only
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Answer B: Take 34 or more consecutive hours off duty

A period of 34 or more consecutive hours off duty resets the 60 or 70 hour calculation so the driver can begin a new period.

Source: ecfr.gov
What blood alcohol concentration disqualifies the holder of a commercial driver license who is operating a commercial vehicle?
1. 0.05 or higher
2. 0.08 or higher
3. 0.10 or higher
4. 0.04 or higher
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Answer D: 0.04 or higher

Commercial drivers are held to 0.04, half the limit that applies to a driver of a passenger car in the same state.

Source: ecfr.gov
A roadside test shows a commercial driver has measurable alcohol in the system but below 0.04. What happens?
1. The driver is warned and allowed to finish the day of work
2. The driver may continue after a rest break of two clear hours
3. The driver is placed out of service for 24 hours
4. The driver is placed out of service until the next inspection
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Answer C: The driver is placed out of service for 24 hours

Any measurable alcohol while on duty results in an immediate 24 hour out of service order, even when the concentration is under the 0.04 limit.

Source: ecfr.gov
What actually lowers the amount of alcohol in the bloodstream?
1. A large meal eaten shortly after the last drink
2. Time
3. Strong coffee taken together with a cold shower
4. Fresh air and light exercise before going on duty
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Answer B: Time

The liver removes alcohol at a fixed rate, so nothing but the passage of time reduces blood alcohol concentration.
A doctor prescribes you a medicine that can cause drowsiness. What should you do?
1. Tell the doctor what you drive and not drive while affected
2. Take a lower dose than prescribed so you can keep driving
3. Take the medicine only at the start of each driving shift
4. Take it with coffee so the two effects cancel each other out
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Answer A: Tell the doctor what you drive and not drive while affected

Both prescription and over the counter medicines can make a driver unsafe, so the medical professional must know the job and the driver must stay out of the seat while affected.
An angry driver has cut in front of you and is now braking hard to provoke you. What is the safest response?
1. Stay close behind so the driver understands you will not be pushed
2. Flash your headlights repeatedly until the driver moves out of the way
3. Pull alongside when possible so the driver can see you are a professional
4. Drop back, avoid eye contact and let the driver go
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Answer D: Drop back, avoid eye contact and let the driver go

Giving an aggressive driver space and no response removes the conflict, while any answering gesture invites escalation you cannot control in a heavy vehicle.
You are the first to arrive at a crash. What is the correct order of actions?
1. Move the damaged vehicles clear, then call for the emergency services
2. Photograph the scene, then wait for the police to arrive and direct you
3. Protect the area, notify the authorities, care for the injured
4. Care for the injured first, then park your own vehicle out of the way
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Answer C: Protect the area, notify the authorities, care for the injured

Preventing a second crash comes first, because an unprotected scene puts the injured and the helpers in more danger than the original collision.
Why should water never be used on an electrical fire or a gasoline fire?
1. It cools the fire too quickly and the metal parts will crack
2. It leaves a residue that prevents the extinguisher from working
3. It spreads the fuel and conducts the current
4. It evaporates before it reaches the base of the burning material
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Answer C: It spreads the fuel and conducts the current

Water carries current back to the person holding the hose and floats burning fuel outward, which is why a B:C rated extinguisher is carried instead.
Which of these counts as a serious traffic violation for a commercial driver license holder?
1. Parking a commercial vehicle at an unmarked loading dock
2. Arriving at a delivery after the appointment time has passed
3. Speeding 15 miles per hour or more above the limit
4. Carrying a load that is 500 pounds under the axle weight limit
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Answer C: Speeding 15 miles per hour or more above the limit

Excessive speeding, reckless driving, improper lane changes, following too closely and texting while driving are all serious traffic violations.

Source: ecfr.gov
A commercial driver is convicted of two serious traffic violations within three years. What is the result?
1. A written warning entered on the driving record
2. Disqualification for 10 days
3. Disqualification for 1 year
4. Disqualification for 60 days
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Answer D: Disqualification for 60 days

Two serious traffic violations in a three year period bring a 60 day disqualification, and a third in the same period raises it to 120 days.

Source: ecfr.gov