Why are you at greater risk when you drive at night?

You cannot see hazards as quickly, so you have less time to respond

Brakes work less well in cool night air

Other drivers are allowed to drive faster at night

The problems of night driving involve which three things?

The driver, the roadway and the vehicle

The cargo, the weather and the route

The engine, the brakes and the tires

Why should you have your eyes checked regularly by an eye specialist?

You may not know your vision is poor unless your eyes are tested

It is needed only to renew a CDL every year

It keeps glare from affecting you at night

Should you wear dark or tinted corrective lenses at night to cut glare?

No, they cut down the light you need to see clearly

Yes, they make oncoming headlights easier to face

Yes, but only on unlit rural roads

How far does a vehicle going 55 mph travel during 2 seconds of glare blindness?

More than half the length of a football field

How does fatigue affect a driver, according to the handbook?

Like alcohol and drugs, it impairs vision and judgment

It slows reactions only after midnight

It affects only drivers over 50

When is sleepiness most pronounced, so that drowsy driving crashes tend to happen?

During the night and in the mid-afternoon

In the early evening and at noon

Which group is named as being at increased risk for a fall-asleep crash?

Drivers with new licenses in daytime

Drivers of small passenger cars

When should you schedule trips to prevent drowsiness?

For the hours you are normally awake

For the middle of the night when roads are empty

Which of these is a warning sign of fatigue?

Trouble remembering the last few miles driven

Feeling hungry before a meal stop

Noticing other drivers speeding

How often should you take breaks on long trips to stay alert?

About every 100 miles or 2 hours

About every 300 miles or 5 hours

What does the handbook say about relying on caffeine to stay awake?

It can help for a few hours but will wear off, so do not rely on it

It prevents fatigue for a full shift

It is the best cure for drowsiness

What is the only safe cure if you are drowsy while driving?

Get off the road and get some sleep

Open the window and turn up the radio

Which lights must be clean and working so you can be seen easily at night?

Reflectors, marker, clearance, tail and identification lights

Only the dome and instrument lights

What should you do when lighting is poor or confusing?

Use your high beams in all traffic

Follow another vehicle closely to use its lights

When should you be especially alert for drunk drivers?

Around the closing times for bars and taverns

How fast should you drive at night with headlights?

Slowly enough to stop within the range of your headlights

At the posted limit, whatever the lighting

Fast enough to keep up with traffic

Why is a clean windshield more important at night?

Bright lights can make dirt on the glass create glare of its own

Wipers do not work as well in the dark

Where should you look to avoid glare from oncoming headlights?

Slightly to the right, at a right lane or edge marking

Directly at the oncoming lights

At the center line to your left

An oncoming driver does not dim his high beams. What should you do?

Keep your low beams on and do not try to get back at him

Flash your high beams back at him

Turn on your high beams until he dims

When should you use high beams?

When it is safe and legal to do so

How should you set your cab lights when driving at night?

Interior light off and instrument lights as low as you can still read

Interior light on so you can see the controls

Instrument lights at full brightness

What is the best advice for driving in fog?

Drive at the speed of the vehicle ahead

When should you slow down for fog?

Only when you can no longer see the road

Which lights should you use for best visibility in fog?

Low beam headlights and fog lights

Why turn on your 4-way flashers in fog?

Vehicles behind you get a quicker chance to notice you

It is a signal that you want to pass

It lets the vehicle ahead know you are following

In fog, what can you use as guides to how the road curves ahead?

The taillights of the vehicle ahead

Should you pass other vehicles in fog?

Yes, to get away from slow traffic

Night, fog, winter and hot weather

Practice this topic72 questions

Questions and answers

Why are you at greater risk when you drive at night?

You cannot see hazards as quickly, so you have less time to respond

In the dark, hazards show up later than in daylight, which leaves less time to react.
Section 2 · 2.11.1 – It's More Dangerous ↗PDF, 41 MB
The problems of night driving involve which three things?

The driver, the roadway and the vehicle

The handbook sorts night driving problems into driver, roadway and vehicle factors.
Section 2 · 2.11.1 – It's More Dangerous ↗PDF, 41 MB
Why should you have your eyes checked regularly by an eye specialist?

You may not know your vision is poor unless your eyes are tested

Poor vision often goes unnoticed until a test finds it, and good vision is critical for safe driving.
Section 2 · 2.11.2 – Driver Factors ↗PDF, 41 MB
Should you wear dark or tinted corrective lenses at night to cut glare?

No, they cut down the light you need to see clearly

Tinted lenses reduce the light reaching your eyes, and at night you need all the light you can get.
Section 2 · 2.11.2 – Driver Factors ↗PDF, 41 MB
How long can it take to recover from being blinded by glare?

Several seconds

Recovery from glare can take several seconds, and even 2 seconds of glare blindness is dangerous.
Section 2 · 2.11.2 – Driver Factors ↗PDF, 41 MB
How far does a vehicle going 55 mph travel during 2 seconds of glare blindness?

More than half the length of a football field

At 55 mph a vehicle covers more than half a football field in 2 seconds.
Section 2 · 2.11.2 – Driver Factors ↗PDF, 41 MB
How does fatigue affect a driver, according to the handbook?

Like alcohol and drugs, it impairs vision and judgment

Fatigue impairs vision and judgment the same way alcohol and drugs do.
Section 2 · 2.11.2 – Driver Factors ↗PDF, 41 MB
About how many police-reported crashes a year does NHTSA estimate are caused by drowsy driving?

100,000

NHTSA estimates 100,000 police-reported crashes each year result from drowsy driving.
Section 2 · 2.11.2 – Driver Factors ↗PDF, 41 MB
When is sleepiness most pronounced, so that drowsy driving crashes tend to happen?

During the night and in the mid-afternoon

Fall-asleep crashes cluster at night and in the mid-afternoon, when people are sleepiest.
Section 2 · At-Risk Groups ↗PDF, 41 MB
After what time are most people especially less alert at night?

After midnight

Most people are less alert at night, especially after midnight and after driving a long time.
Section 2 · At-Risk Groups ↗PDF, 41 MB
Which group is named as being at increased risk for a fall-asleep crash?

Long-haul commercial drivers

Young males, shift workers, commercial drivers (especially long-haul) and people with sleep problems are at higher risk.
Section 2 · At-Risk Groups ↗PDF, 41 MB
At least what share of all heavy truck crashes involve fatigue?

15%

Fatigue is involved in at least 15 percent of heavy truck crashes.
Section 2 · At-Risk Groups ↗PDF, 41 MB
A study of long-haul truck drivers found they averaged how much sleep per day?

Less than 5 hours

The study of 80 long-haul drivers found an average of less than 5 hours of sleep a day.
Section 2 · At-Risk Groups ↗PDF, 41 MB
For each truck driver killed in a crash, how many other people are killed?

Three to four

Each truck driver death comes with another three to four deaths.
Section 2 · At-Risk Groups ↗PDF, 41 MB
Between which hours do many heavy motor vehicle accidents occur?

Between midnight and 6 a.m.

Driving through the night is a fatigue warning sign, and many heavy vehicle accidents happen between midnight and 6 a.m.
Section 2 · Warning Signs of Fatigue ↗PDF, 41 MB
By how much does working more than 60 hours a week increase your crash risk?

40%

Working more than 60 hours a week raises your risk by 40 percent.
Section 2 · Warning Signs of Fatigue ↗PDF, 41 MB
Which kind of medication is listed as sedating and a sign you should stop and rest?

Antihistamines

Antidepressants, cold tablets and antihistamines can make you drowsy.
Section 2 · Warning Signs of Fatigue ↗PDF, 41 MB
How much sleep do adults need to stay alert?

8 to 9 hours

Getting adequate sleep before a trip means 8 to 9 hours for adults.
Section 2 · Warning Signs of Fatigue ↗PDF, 41 MB
When should you schedule trips to prevent drowsiness?

For the hours you are normally awake

Plan trips for your normal waking hours, not the middle of the night.
Section 2 · Warning Signs of Fatigue ↗PDF, 41 MB
Which of these is a warning sign of fatigue?

Trouble remembering the last few miles driven

Not remembering the last few miles, missing exits or signs are signs you should stop and rest.
Section 2 · Warning Signs of Fatigue ↗PDF, 41 MB
Hitting a shoulder rumble strip may be a sign of what?

Fatigue

Drifting from your lane, following too closely or hitting a rumble strip are signs of fatigue.
Section 2 · Warning Signs of Fatigue ↗PDF, 41 MB
If you notice signs of fatigue, how long a nap does the handbook suggest?

15 to 20 minutes

Stop driving and sleep for the night, or take a 15 to 20 minute nap.
Section 2 · Warning Signs of Fatigue ↗PDF, 41 MB
How much does getting 6 hours of sleep or less raise your risk?

It triples your risk

Being sleep deprived, with 6 hours of sleep or less, triples your crash risk.
Section 2 · Are You At Risk? ↗PDF, 41 MB
How often should you take breaks on long trips to stay alert?

About every 100 miles or 2 hours

Periodic breaks about every 100 miles or 2 hours help you stay alert.
Section 2 · Are You At Risk? ↗PDF, 41 MB
What does the handbook say about relying on caffeine to stay awake?

It can help for a few hours but will wear off, so do not rely on it

Caffeine may raise awareness for a few hours, but it wears off and does not prevent fatigue.
Section 2 · Are You At Risk? ↗PDF, 41 MB
What is the only safe cure if you are drowsy while driving?

Get off the road and get some sleep

Nothing but sleep fixes drowsiness, so get off the road and rest.
Section 2 · Are You At Risk? ↗PDF, 41 MB
Which lights must be clean and working so you can be seen easily at night?

Reflectors, marker, clearance, tail and identification lights

Reflectors and marker, clearance, tail and identification lights all help others see you.
Section 2 · 2.11.4 – Vehicle Factors ↗PDF, 41 MB
On most roads at night, what will you probably have to depend on to see?

Your headlights

Many areas are poorly lit, so on most roads your headlights are your only light.
Section 2 · 2.11.3 – Roadway Factors ↗PDF, 41 MB
What should you do when lighting is poor or confusing?

Drive slower

Slow down when lighting is poor or confusing so you can stop in the distance you can see.
Section 2 · 2.11.3 – Roadway Factors ↗PDF, 41 MB
When should you be especially alert for drunk drivers?

Around the closing times for bars and taverns

Drunk drivers are most common around bar closing times.
Section 2 · 2.11.3 – Roadway Factors ↗PDF, 41 MB
About how far ahead can you see with low beam headlights?

About 250 feet

Low beams light about 250 feet ahead.
Section 2 · 2.11.4 – Vehicle Factors ↗PDF, 41 MB
About how far ahead can you see with high beam headlights?

About 350 to 500 feet

High beams let you see about 350 to 500 feet ahead.
Section 2 · 2.11.4 – Vehicle Factors ↗PDF, 41 MB
How fast should you drive at night with headlights?

Slowly enough to stop within the range of your headlights

Your stopping distance must stay within your sight distance, which at night is your headlight range.
Section 2 · 2.11.4 – Vehicle Factors ↗PDF, 41 MB
Dirty headlights may give how much of the light they should?

Only half

Dirt can cut headlight output in half, so keep them clean.
Section 2 · 2.11.4 – Vehicle Factors ↗PDF, 41 MB
Who should make sure your headlights are adjusted properly?

A qualified person

Headlights out of adjustment give a poor view and blind others, so have a qualified person adjust them.
Section 2 · 2.11.4 – Vehicle Factors ↗PDF, 41 MB
Why is a clean windshield more important at night?

Bright lights can make dirt on the glass create glare of its own

At night bright lights turn dirt on the windshield or mirrors into glare that blocks your view.
Section 2 · 2.11.4 – Vehicle Factors ↗PDF, 41 MB
Should you wear sunglasses at night?

No

Sunglasses cut light you need, so do not wear them at night.
Section 2 · 2.11.5 – Night Driving Procedures ↗PDF, 41 MB
Within what distance of an oncoming vehicle should you dim your headlights?

500 feet

Dim your lights within 500 feet of an oncoming vehicle.
Section 2 · 2.11.5 – Night Driving Procedures ↗PDF, 41 MB
When following another vehicle, within what distance should you use low beams?

500 feet

Your high beams can shine in the mirrors of a vehicle ahead, so dim them within 500 feet when following.
Section 2 · 2.11.5 – Night Driving Procedures ↗PDF, 41 MB
Where should you look to avoid glare from oncoming headlights?

Slightly to the right, at a right lane or edge marking

Do not look straight at oncoming lights, look slightly to the right at a lane or edge line.
Section 2 · 2.11.5 – Night Driving Procedures ↗PDF, 41 MB
An oncoming driver does not dim his high beams. What should you do?

Keep your low beams on and do not try to get back at him

Answering with your own high beams increases glare and the chance of a crash.
Section 2 · 2.11.5 – Night Driving Procedures ↗PDF, 41 MB
When should you use high beams?

When it is safe and legal to do so

Always using low beams seriously cuts how far you can see, so use high beams when safe and legal.
Section 2 · 2.11.5 – Night Driving Procedures ↗PDF, 41 MB
How should you set your cab lights when driving at night?

Interior light off and instrument lights as low as you can still read

A bright cab makes it harder to see outside.
Section 2 · 2.11.5 – Night Driving Procedures ↗PDF, 41 MB
What is the best advice for driving in fog?

Don't drive in it

If you can, pull off into a rest area or truck stop until visibility improves.
Section 2 · 2.12 – Driving in Fog ↗PDF, 41 MB
When should you slow down for fog?

Before you enter the fog

Fog often thickens quickly, so reduce speed before you drive into it.
Section 2 · 2.12 – Driving in Fog ↗PDF, 41 MB
Which lights should you use for best visibility in fog?

Low beam headlights and fog lights

Low beams and fog lights give the best view in fog, even in daytime.
Section 2 · 2.12 – Driving in Fog ↗PDF, 41 MB
Why turn on your 4-way flashers in fog?

Vehicles behind you get a quicker chance to notice you

Flashers help drivers approaching from behind see you sooner.
Section 2 · 2.12 – Driving in Fog ↗PDF, 41 MB
In fog, what can you use as guides to how the road curves ahead?

Roadside highway reflectors

Taillights ahead may belong to a vehicle that is off the road, so use roadside reflectors as a guide.
Section 2 · 2.12 – Driving in Fog ↗PDF, 41 MB
Should you pass other vehicles in fog?

No, avoid passing

Passing in fog is dangerous because you cannot see what is ahead.
Section 2 · 2.12 – Driving in Fog ↗PDF, 41 MB
What tread depth is required in every major groove on front tires?

At least 4/32 inch

Front tires need at least 4/32 inch in every major groove.
Section 2 · 2.13.1 – Vehicle Checks ↗PDF, 41 MB
What tread depth is required on tires other than the front tires?

At least 2/32 inch

Tires other than the front ones need at least 2/32 inch of tread.
Section 2 · 2.13.1 – Vehicle Checks ↗PDF, 41 MB
Besides the right number of tire chains, what should you carry for winter driving?

Extra cross-links

Carry the right number of chains plus extra cross-links, and make sure they fit your drive tires.
Section 2 · 2.13.1 – Vehicle Checks ↗PDF, 41 MB
What can happen if the radiator shutters freeze shut or the winterfront is closed too much?

The engine may overheat and stop

Too little air through the radiator can make the engine overheat and stop.
Section 2 · 2.13.1 – Vehicle Checks ↗PDF, 41 MB
Why are exhaust leaks especially dangerous in winter?

Poisonous carbon monoxide can leak into a closed cab

With the windows up, carbon monoxide from a leak can make you sleepy and even kill you.
Section 2 · 2.13.1 – Vehicle Checks ↗PDF, 41 MB
What does a lack of spray from other vehicles on a wet-looking road tell you?

Ice has formed on the road

When tires stop throwing spray, the water on the road has frozen.
Section 2 · 2.13.2 – Driving ↗PDF, 41 MB
Why should you not use the engine brake or speed retarder on slippery roads?

They can cause the driving wheels to skid

On slippery surfaces engine brakes and retarders can make the drive wheels skid.
Section 2 · 2.13.2 – Driving ↗PDF, 41 MB
What happens to the road as the temperature rises to the point where ice begins to melt?

It becomes even more slippery

Melting ice is more slippery than solid ice, so slow down more.
Section 2 · 2.13.2 – Driving ↗PDF, 41 MB
How should you set your following distance on slippery roads?

Keep a longer following distance

Do not drive alongside others and leave more room ahead on slippery roads.
Section 2 · 2.13.2 – Driving ↗PDF, 41 MB
What can wet brakes cause?

Weak braking, wheel lockups, pulling to one side and jackknife

Water in the brakes can make them weak, uneven or grabby.
Section 2 · 2.13.2 – Driving ↗PDF, 41 MB
When you must drive through deep water, how should you use the brakes?

Keep light pressure on them while crossing

Light brake pressure keeps mud, silt, sand and water from getting into the brakes.
Section 2 · 2.13.2 – Driving ↗PDF, 41 MB
What should you do after driving out of deep water?

Keep light pressure on the brakes for a short distance to dry them

Light braking for a short distance heats and dries the brakes, then make a test stop.
Section 2 · 2.13.2 – Driving ↗PDF, 41 MB
What can happen if you apply too much brake pressure and accelerator at the same time?

You can overheat the brake drums and linings

Pressing hard on both pedals together can overheat drums and linings.
Section 2 · 2.13.2 – Driving ↗PDF, 41 MB
How often should you inspect your tires when driving in very hot weather?

Every two hours or every 100 miles

In very hot weather check the tires every two hours or every 100 miles.
Section 2 · 2.14.1 – Vehicle Checks ↗PDF, 41 MB
Tire pressure has risen on a hot day. What should you do?

Do not let air out

Pressure rises with heat, and if you let air out it will be too low once the tires cool.
Section 2 · 2.14.1 – Vehicle Checks ↗PDF, 41 MB
What should you do if a tire is too hot to touch?

Remain stopped until the tire cools off

A tire too hot to touch could blow out or catch fire, so wait until it cools.
Section 2 · 2.14.1 – Vehicle Checks ↗PDF, 41 MB
Besides lubricating, what does engine oil do?

It helps keep the engine cool

Engine oil helps cool the engine as well as lubricate it.
Section 2 · 2.14.1 – Vehicle Checks ↗PDF, 41 MB
When is it safe to remove the radiator cap or open the pressurized cooling system?

Only after the system has cooled

Steam and boiling water can spray under pressure, so wait until the system has cooled.
Section 2 · 2.14.1 – Vehicle Checks ↗PDF, 41 MB
How can you tell the radiator cap is probably cool enough to open?

You can touch it with your bare hand

If you can touch the cap with a bare hand, it is probably cool enough.
Section 2 · 2.14.1 – Vehicle Checks ↗PDF, 41 MB
When adding coolant to a system without a recovery tank, how far do you first turn the radiator cap?

Slowly to the first stop, which releases the pressure seal

Turn the cap slowly to the first stop, step back while pressure releases, then remove it.
Section 2 · 2.14.1 – Vehicle Checks ↗PDF, 41 MB
What can loose engine belts cause?

Overheating, because the water pump or fan will not turn properly

Loose belts may not turn the water pump or fan, which leads to overheating.
Section 2 · 2.14.1 – Vehicle Checks ↗PDF, 41 MB
Why should you watch for spots where tar bleeds to the surface in hot weather?

They are very slippery

Tar that rises to the surface in hot weather makes very slippery spots.
Section 2 · 2.14.2 – Driving ↗PDF, 41 MB
Why should you go slowly in very hot weather?

High speeds create more heat for tires and the engine

Speed builds heat, which raises the chance of tire failure, fire and engine failure.
Section 2 · 2.14.2 – Driving ↗PDF, 41 MB

Night, fog, winter and hot weather

Questions and answers

Why are you at greater risk when you drive at night?

The problems of night driving involve which three things?

Why should you have your eyes checked regularly by an eye specialist?

Should you wear dark or tinted corrective lenses at night to cut glare?

How long can it take to recover from being blinded by glare?

How far does a vehicle going 55 mph travel during 2 seconds of glare blindness?

How does fatigue affect a driver, according to the handbook?

About how many police-reported crashes a year does NHTSA estimate are caused by drowsy driving?

When is sleepiness most pronounced, so that drowsy driving crashes tend to happen?

After what time are most people especially less alert at night?

Which group is named as being at increased risk for a fall-asleep crash?

At least what share of all heavy truck crashes involve fatigue?

A study of long-haul truck drivers found they averaged how much sleep per day?

For each truck driver killed in a crash, how many other people are killed?

Between which hours do many heavy motor vehicle accidents occur?

By how much does working more than 60 hours a week increase your crash risk?

Which kind of medication is listed as sedating and a sign you should stop and rest?

How much sleep do adults need to stay alert?

When should you schedule trips to prevent drowsiness?

Which of these is a warning sign of fatigue?

Hitting a shoulder rumble strip may be a sign of what?

If you notice signs of fatigue, how long a nap does the handbook suggest?

How much does getting 6 hours of sleep or less raise your risk?

How often should you take breaks on long trips to stay alert?

What does the handbook say about relying on caffeine to stay awake?

What is the only safe cure if you are drowsy while driving?

Which lights must be clean and working so you can be seen easily at night?

On most roads at night, what will you probably have to depend on to see?

What should you do when lighting is poor or confusing?

When should you be especially alert for drunk drivers?

About how far ahead can you see with low beam headlights?

About how far ahead can you see with high beam headlights?

How fast should you drive at night with headlights?

Dirty headlights may give how much of the light they should?

Who should make sure your headlights are adjusted properly?

Why is a clean windshield more important at night?

Should you wear sunglasses at night?

Within what distance of an oncoming vehicle should you dim your headlights?

When following another vehicle, within what distance should you use low beams?

Where should you look to avoid glare from oncoming headlights?

An oncoming driver does not dim his high beams. What should you do?

When should you use high beams?

How should you set your cab lights when driving at night?

What is the best advice for driving in fog?

When should you slow down for fog?

Which lights should you use for best visibility in fog?

Why turn on your 4-way flashers in fog?

In fog, what can you use as guides to how the road curves ahead?

Should you pass other vehicles in fog?

What tread depth is required in every major groove on front tires?

What tread depth is required on tires other than the front tires?

Besides the right number of tire chains, what should you carry for winter driving?

What can happen if the radiator shutters freeze shut or the winterfront is closed too much?

Why are exhaust leaks especially dangerous in winter?

What does a lack of spray from other vehicles on a wet-looking road tell you?

Why should you not use the engine brake or speed retarder on slippery roads?

What happens to the road as the temperature rises to the point where ice begins to melt?

How should you set your following distance on slippery roads?

What can wet brakes cause?

When you must drive through deep water, how should you use the brakes?

What should you do after driving out of deep water?

What can happen if you apply too much brake pressure and accelerator at the same time?

How often should you inspect your tires when driving in very hot weather?

Tire pressure has risen on a hot day. What should you do?

What should you do if a tire is too hot to touch?

Besides lubricating, what does engine oil do?

When is it safe to remove the radiator cap or open the pressurized cooling system?

How can you tell the radiator cap is probably cool enough to open?

When adding coolant to a system without a recovery tank, how far do you first turn the radiator cap?

What can loose engine belts cause?

Why should you watch for spots where tar bleeds to the surface in hot weather?

Why should you go slowly in very hot weather?

Questions and answers by topic