Commercial driver’s license (CDL) knowledge tests · California DMV
Night, Fog, Winter and Hot Weather
Questions and answers
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Why are you at greater risk when you drive at night?
Hazards cannot be seen as quickly, so there is less time to respond
In the dark, drivers see hazards later than in daylight and have less time to react.
Section 2 · 2.11.1 – It Is More Dangerous ↗ -
The problems of night driving involve which three things?
The driver, the roadway and the vehicle
The handbook groups night driving problems into driver, roadway and vehicle factors.
Section 2 · 2.11.1 – It Is More Dangerous ↗ -
Your license has a corrective lenses restriction. What does that mean for moving a vehicle?
It is illegal to move a vehicle without your corrective lenses
With that restriction, moving a vehicle without corrective lenses is illegal, even for a short distance.
Section 2 · 2.11.2 – Driver Factors ↗ -
Why should you keep an extra set of corrective lenses in your vehicle?
So you can still drive safely if your normal ones are broken or lost
A spare set lets you keep driving safely if your usual lenses are broken or lost.
Section 2 · 2.11.2 – Driver Factors ↗ -
Should you wear dark or tinted corrective lenses at night to reduce glare?
No, they cut down the light you need to see clearly
Tinted lenses reduce the light reaching your eyes, which you need at night.
Section 2 · 2.11.2 – Driver Factors ↗ -
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 can be dangerous.
Section 2 · 2.11.2 – Driver Factors ↗ -
How far does a vehicle going 55 mph travel during 2 seconds of glare blindness?
More than half the length of a football field
In 2 seconds at 55 mph a vehicle covers more than half a football field.
Section 2 · 2.11.2 – Driver Factors ↗ -
How does the handbook define fatigue?
Physical or mental tiredness
Fatigue is physical or mental tiredness caused by strain, repetitive tasks, illness or lack of sleep.
Section 2 · 2.11.2 – Driver Factors ↗ -
Fatigue is compared to alcohol and drugs because it does what?
Impairs your vision and judgment
Like alcohol and drugs, fatigue impairs vision and judgment.
Section 2 · 2.11.2 – Driver Factors ↗ -
According to NHTSA, about how many police-reported accidents a year result from drowsy driving?
100,000
NHTSA estimates 100,000 police-reported accidents a year are caused by drowsy driving.
Section 2 · 2.11.2 – Driver Factors ↗ -
In the Sleep in America Poll, what share of Americans said they had driven while feeling sleepy?
60 percent
Sixty percent had driven while sleepy, and 36 percent admitted to actually falling asleep at the wheel.
Section 2 · 2.11.2 – Driver Factors ↗ -
In the same poll, what share admitted to having actually fallen asleep at the wheel?
36 percent
More than a third, 36 percent, admitted to falling asleep at the wheel.
Section 2 · 2.11.2 – Driver Factors ↗ -
How much does getting 6 hours of sleep or less raise your risk?
It triples your risk
Six hours of sleep or less triples the risk.
Section 2 · 2.11.2 – Driver Factors ↗ -
Between which hours do many heavy motor vehicle accidents occur?
Midnight and 6 a.m.
Many heavy vehicle accidents happen between midnight and 6 a.m., when people would normally be asleep.
Section 2 · 2.11.2 – Driver Factors ↗ -
Working more than how many hours a week is listed as a fatigue risk?
60 hours
Working more than 60 hours a week increases your risk by 40 percent.
Section 2 · 2.11.2 – Driver Factors ↗ -
By how much does working more than 60 hours a week increase your risk?
40 percent
The handbook gives a 40 percent increase in risk.
Section 2 · 2.11.2 – Driver Factors ↗ -
Which of these are named as sedating medications to consider before you drive?
Antidepressants, cold tablets and antihistamines
Antidepressants, cold tablets and antihistamines can all make you drowsy.
Section 2 · 2.11.2 – Driver Factors ↗ -
At which times of day is sleepiness most pronounced?
During the night and in the mid-afternoon
Drowsy-driving accidents cluster at night and in the mid-afternoon.
Section 2 · 2.11.2 – Driver Factors ↗ -
Which groups does research identify as being at increased risk of a fall-asleep accident?
Young males, shift workers and commercial drivers, especially long-haul
Young males, shift workers, commercial drivers and people with sleep disorders or sleep deprivation are at higher risk.
Section 2 · 2.11.2 – Driver Factors ↗ -
At least what share of all heavy truck accidents involve fatigue?
15 percent
At least 15 percent of heavy truck accidents involve fatigue.
Section 2 · 2.11.2 – Driver Factors ↗ -
A study of 80 long-haul truck drivers found they averaged how much sleep per day?
Less than 5 hours
The drivers in the study averaged less than 5 hours of sleep a day.
Section 2 · 2.11.2 – Driver Factors ↗ -
What did the NTSB report about accidents leading to a truck driver’s death?
Drowsy driving was probably the cause of more than half of them
The NTSB reported drowsy driving as the probable cause of more than half of those accidents.
Section 2 · 2.11.2 – Driver Factors ↗ -
For each truck driver killed, how many other people are killed?
Another 3 to 4 people
For each truck driver fatality, another 3 to 4 people die.
Section 2 · 2.11.2 – Driver Factors ↗ -
Which of these is a warning sign of fatigue?
Trouble remembering the last few miles driven
Missing exits or signs and not remembering the last few miles are signs that you should stop and rest.
Section 2 · 2.11.2 – Driver Factors ↗ -
You keep drifting from your lane and hit a shoulder rumble strip. What is this a sign of?
Fatigue
Drifting, following too closely and hitting a rumble strip are listed as warning signs of fatigue.
Section 2 · 2.11.2 – Driver Factors ↗ -
You notice signs of fatigue. If you do not stop for the night, how long a nap does the handbook suggest?
15 to 20 minutes
Stop driving and either sleep for the night or take a 15 to 20 minute nap.
Section 2 · 2.11.2 – Driver Factors ↗ -
What does the handbook say about trying to “push on” when you are tired?
It is far more dangerous than most drivers think
Pushing on while tired is a major cause of fatal accidents.
Section 2 · 2.11.2 – Driver Factors ↗ -
How much sleep do adults need to maintain alertness?
8 to 9 hours
Adults need 8 to 9 hours of sleep.
Section 2 · 2.11.2 – Driver Factors ↗ -
To prevent drowsiness, for which hours should you schedule trips?
The hours you are normally awake
Plan trips for your normal waking hours, not the middle of the night.
Section 2 · 2.11.2 – Driver Factors ↗ -
How often should you take a break during a long trip to stay alert?
About every 100 miles or 2 hours
Take periodic breaks about every 100 miles or 2 hours.
Section 2 · 2.11.2 – Driver Factors ↗ -
What does the handbook say about using caffeine to stay alert?
It can help for a few hours, but do not rely on it to prevent fatigue
Caffeine can raise awareness for a few hours, but it wears off and is not a cure for fatigue.
Section 2 · 2.11.2 – Driver Factors ↗ -
What does the handbook say about using drugs to stay awake?
They may keep you awake for a while but will not make you alert
Being awake is not the same as being alert. Avoid drugs.
Section 2 · 2.11.2 – Driver Factors ↗ -
What is the only safe cure when you are drowsy?
Get off the road and sleep
Nothing replaces sleep. If you are drowsy, leave the road and sleep.
Section 2 · 2.11.2 – Driver Factors ↗ -
Which of these helps you stay alert while driving?
Keeping cool with an open window or the air conditioner
Keep cool and avoid heavy foods.
Section 2 · 2.11.2 – Driver Factors ↗ -
On most roads at night, what will you probably have to depend on entirely to see?
Your headlights
Many areas have poor lighting, so on most roads you rely entirely on your headlights.
Section 2 · 2.11.3 – Roadway Factors ↗ -
How should you drive when the lighting is poor or confusing?
Slowly enough to be sure you can stop in the distance you can see ahead
Slow down so that your stopping distance fits within what you can see.
Section 2 · 2.11.3 – Roadway Factors ↗ -
When should you be especially alert for drunk drivers?
Around the closing times of bars and taverns
Impaired drivers are most likely to be on the road around closing time.
Section 2 · 2.11.3 – Roadway Factors ↗ -
Which behaviour suggests a driver may be under the influence?
Trouble staying in the lane and stopping without reason
Watch for drivers who cannot hold their lane or speed, or who stop for no reason.
Section 2 · 2.11.3 – Roadway Factors ↗ -
About how far ahead can you see with low beams?
About 250 feet
Low beams light the road for about 250 feet.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
About how far ahead can you see with high beams?
About 350 to 500 feet
High beams let you see about 350 to 500 feet ahead.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
How should your speed relate to your headlights at night?
You must be able to stop within the range of your headlights
Keep your stopping distance within your sight distance, or you will not be able to stop for a hazard you see.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
How much light may dirty headlights give?
Only half the light they should
Dirty headlights may give only half their normal light, which also makes you harder to see.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
What can happen if your headlights are out of adjustment?
They give you a poor view and can blind other drivers
Misaimed headlights do not light the road properly and can blind others. Have a qualified person adjust them.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
Between which times must your headlights be on?
From a half hour after sunset to a half hour before sunrise
Headlights are required from a half hour after sunset until a half hour before sunrise.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
It is daytime, but rain requires you to use your windshield wipers. What about your headlights?
They must be turned on
Headlights must be on whenever weather requires the use of windshield wipers.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
Headlights are required when you cannot clearly see a person or vehicle at what distance?
1,000 feet
If visibility is too poor to clearly see a person or vehicle 1,000 feet away, headlights must be on.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
On a hazy morning you cannot clearly make out vehicles 800 feet ahead. Do you need headlights?
Yes, because visibility is under 1,000 feet
The rule is based on visibility, not only time of day. Under 1,000 feet of clear visibility, headlights go on.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
May a vehicle be driven with only its parking lights on?
No
No vehicle may be driven with only the parking lights on.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
When may parking lights be used while driving?
As signals, or when the headlamps are also on
Parking lights may be used as signals or together with lighted headlamps.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
Besides headlights, what must be clean and working so that you can be seen easily at night?
Reflectors, marker lights, clearance lights, taillights and identification lights
All of these lights and reflectors help others see you.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
Why is a clean windshield even more important at night than in the daytime?
Bright lights make dirt on the glass create a glare of its own
Bright lights turn dirt on the windshield or mirrors into glare that blocks your view.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
For safe night driving, which sides of the windshield should you clean?
The inside and the outside
Clean both the inside and outside of the windshield.
Section 2 · 2.11.4 – Vehicle Factors ↗ -
What does the handbook say about wearing sunglasses at night?
Do not wear them
Sunglasses help against glare in daylight, but they should not be worn at night.
Section 2 · 2.11.5 – Night Driving Procedures ↗ -
Before a night trip, what should your vehicle inspection pay particular attention to?
All lights and reflectors, cleaning those you can reach
Check every light and reflector and clean the ones you can reach.
Section 2 · 2.11.5 – Night Driving Procedures ↗ -
Within what distance of an oncoming vehicle must you dim your lights?
500 feet
Dim your lights within 500 feet of an oncoming vehicle.
Section 2 · 2.11.5 – Night Driving Procedures ↗ -
You are following another vehicle at night. Within what distance must you dim your lights?
500 feet
The 500-foot rule also applies when you follow another vehicle, because your lights shine in its mirrors.
Section 2 · 2.11.5 – Night Driving Procedures ↗ -
Where should you look when an oncoming vehicle’s lights are bright?
Slightly to the right, at the right lane or edge marking
Do not look directly at the lights. Look slightly right toward the lane or edge marking.
Section 2 · 2.11.5 – Night Driving Procedures ↗ -
An oncoming driver does not switch to low beams. What should you do with your own lights?
Keep them on low beam
Using your high beams to “get back at them” increases glare and the chance of an accident.
Section 2 · 2.11.5 – Night Driving Procedures ↗ -
What does the handbook say about drivers who always use low beams?
It is a mistake that seriously cuts down how far they can see
Use high beams whenever it is safe and legal, which means when you are not within 500 feet of an approaching vehicle.
Section 2 · 2.11.5 – Night Driving Procedures ↗ -
How should you set the lights inside the cab 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 ↗ -
You feel sleepy at night. What quick check does the handbook suggest, if you can do it safely?
Look at yourself in a mirror, and stop driving if you look or feel sleepy
People often do not realise how close they are to falling asleep. If you look or feel sleepy, stop.
Section 2 · 2.11.5 – Night Driving Procedures ↗ -
What is the best advice for driving in fog?
Do not drive in it, and pull off at a rest area or truck stop until it clears
The handbook says the best advice is not to drive in fog at all.
Section 2 · 2.12 – Driving in Fog ↗ -
When should you slow down for fog?
Before you enter it
Reduce speed before entering the fog, and do not assume it will thin out.
Section 2 · 2.12 – Driving in Fog ↗ -
You have just entered a fog bank. What should you assume about it?
Do not assume it will thin out
Fog is often unexpected and visibility can get worse quickly.
Section 2 · 2.12 – Driving in Fog ↗ -
Which lights give the best visibility in fog?
Low-beam headlights and fog lights, even in daytime
Use low beams and fog lights in fog, day or night.
Section 2 · 2.12 – Driving in Fog ↗ -
Why should you turn on your 4-way emergency flashers in fog?
So vehicles coming up from behind have a better chance to notice you
The flashers help drivers approaching from behind to notice your vehicle.
Section 2 · 2.12 – Driving in Fog ↗ -
In fog you see taillights ahead. Why should you not trust them to show where the road goes?
The vehicle may not be on the road at all
Lights ahead may belong to a vehicle stopped on the side of the roadway.
Section 2 · 2.12 – Driving in Fog ↗ -
What can you use as a guide to how the road curves ahead in fog?
Roadside highway reflectors
Roadside reflectors show the path of the road.
Section 2 · 2.12 – Driving in Fog ↗ -
What does the handbook say about passing other vehicles in fog?
Avoid it
Avoid passing in fog, and listen for traffic you cannot see.
Section 2 · 2.12 – Driving in Fog ↗ -
What does the handbook say about stopping along the side of the road in fog?
Do not do it unless absolutely necessary
Stopping on the roadside in fog is dangerous. It is better to pull off into a rest area or truck stop.
Section 2 · 2.12 – Driving in Fog ↗ -
How can you check that there is enough antifreeze in the cooling system before winter driving?
With a special coolant tester
A special coolant tester shows whether the antifreeze will protect against freezing.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
Why must wiper blades press hard enough against the windshield in winter?
Otherwise they may not sweep off snow properly
Blades need enough pressure to wipe the glass clean and clear snow.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
What should you put in the washer reservoir to stop the washer liquid from freezing?
Windshield washer antifreeze
Windshield washer antifreeze keeps the washer liquid from freezing.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
Your wipers fail in winter weather and you cannot see well enough. What should you do?
Stop safely and fix the problem
If you cannot see well enough while driving, stop safely and fix the problem.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
Before a winter trip you measure 3/32 inch of tread in a major groove of a front tire. Is that enough?
No, front tires need at least 4/32 inch
Front tires need at least 4/32 inch. Other tires need at least 2/32 inch.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
What is the minimum tread depth on tires other than the front tires?
2/32 inch
Tires other than the front ones need at least 2/32 inch, and more is better.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
How should you find out whether you have enough tread for safe driving?
Use a gauge
A tread gauge tells you whether the depth is enough.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
What should you carry for winter conditions where you cannot drive without chains?
The right number of chains and 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 ↗ -
Tire chains must fit which tires?
Your drive tires
Make sure the chains will fit the drive tires.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
What should you look for when checking tire chains?
Broken hooks, worn or broken cross-links, and bent or broken side chains
Check hooks, cross-links and side chains for damage.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
When should you learn how to put tire chains on?
Before you need to do it in snow and ice
Practise fitting chains ahead of time, not in the middle of a storm.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
Why should you remove all ice and snow from hand holds, steps and deck plates?
To reduce the danger of slipping
Clearing them reduces the chance of slipping when you climb on or off.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
What can happen if the radiator shutters freeze shut or the winterfront is closed too much?
The engine may overheat and stop
Blocked airflow can make the engine overheat and stop, even in winter.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
What effect does carbon monoxide leaking into the cab have on you?
It makes you sleepy, and in large amounts it can kill you
Carbon monoxide from exhaust leaks causes sleepiness and can be fatal.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
When are exhaust system leaks especially dangerous?
When cab ventilation may be poor, such as with the windows rolled up
With the windows up, leaking exhaust gas can build up in the cab.
Section 2 · 2.13.1 – Vehicle Checks ↗ -
The road is very slippery. What does the handbook say you should do?
Not drive at all, and stop at the first safe place
On very slippery roads you should not drive. Stop at the first safe place.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
What does a lack of spray from other vehicles on a wet-looking road tell you?
Ice has formed on the road
When there is no spray, the water on the road has frozen.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
You find ice on your mirrors and wiper blades. What does this suggest about the road?
The road is most likely icy too
Ice on mirrors and wiper blades is a sign that the road will be icy as well.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
Where should you especially check for ice on the road?
On bridges and overpasses
Bridges and overpasses are named as places to check for ice.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
Should you use the engine brake or speed retarder on a slippery road?
No, they can make the driving wheels skid
On slippery surfaces the engine brake or retarder can cause the driving wheels to skid.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
What happens to an icy road as the temperature rises to the point where ice begins to melt?
It becomes even more slippery
Melting ice is wetter and more slippery, so slow down more.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
How should you handle curves on a slippery road?
Take them at slower speeds and do not brake while in the curve
Slow down before the curve and stay off the brakes while in it.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
What does the handbook say about passing slower vehicles on a slippery road?
Do not pass unless necessary
Go slowly, keep a steady speed and avoid passing unless you have to.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
How should you position your vehicle relative to others on a slippery road?
Do not drive alongside them, and keep a longer following distance
Keep space around you. Do not drive alongside other vehicles and leave more room in front.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
On a slippery road you see a traffic jam ahead. What should you do?
Slow down or stop to wait for it to clear
Anticipate stops early, slow gradually and wait for the jam to clear.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
How should you treat snowplows and salt or sand trucks?
Watch for them and give them plenty of room
Give these vehicles plenty of room.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
What can water in the brakes cause the brakes to do?
Be weak, apply unevenly or grab
Wet brakes can be weak, uneven or grabbing.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
Which of these can result from wet brakes if you pull a trailer?
A jackknife
Wet brakes can cause lack of braking power, wheel lockups, pulling to one side and a jackknife.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
You cannot avoid driving through deep water. What should you do first?
Slow down and place the transmission in a low gear
Slow down and select a low gear before entering the water.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
Why should you gently put on the brakes while driving through water?
It presses the linings against the drums or discs and keeps mud, sand and water out
Light brake pressure closes the gap so mud, silt, sand and water cannot get in.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
How should you cross the water once the brakes are gently applied?
Increase engine rpm and keep light pressure on the brakes
Raise the engine rpm and cross with light pressure on the brakes.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
After you leave the water, why keep light pressure on the brakes for a short distance?
To heat them up and dry them out
A short stretch of light braking heats and dries the brakes.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
What should you do before making a test stop after driving through water?
Check behind you to make sure no one is following
Make the test stop only when it is safe, after checking that no one is behind you.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
What can happen if you apply too much brake pressure and accelerator at the same time while drying the brakes?
You can overheat the brake drums and linings
Too much brake and throttle together overheats the drums and linings.
Section 2 · 2.13.2 – Driving on Slippery Surfaces ↗ -
How often should you inspect the tires when driving in very hot weather?
Every 2 hours or every 100 miles
In very hot weather, check the tires every 2 hours or every 100 miles.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
Tire pressure has risen in hot weather. Should you let some air out?
No, the pressure will be too low when the tires cool off
Air pressure rises with temperature. If you let air out, the tires will be under-inflated once they cool.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
A tire is too hot to touch. What should you do?
Remain stopped until the tire cools off
Stay stopped until it cools. Otherwise the tire may blow out or catch fire.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
What may happen if you keep driving on a tire that is too hot to touch?
It may blow out or catch fire
An overheated tire can blow out or catch fire.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
Besides lubricating, what does engine oil do that matters in hot weather?
It helps keep the engine cool
Engine oil helps cool the engine, so make sure there is enough.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
Is antifreeze useful to the engine in hot conditions?
Yes, it helps under hot conditions as well as cold
The cooling system needs enough water and antifreeze in hot weather too.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
The coolant temperature gauge goes above the highest safe temperature. What should you do?
Stop as soon as safely possible and try to find out what is wrong
An overheating engine could fail or even catch fire.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
When can coolant be added safely with the engine at operating temperature?
When the container is not part of the pressurized system
A recovery or overflow container outside the pressurized system can be opened while the engine is hot.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
When may you remove the radiator cap?
Only after the system has cooled
Never remove the radiator cap or any part of the pressurized system until it has cooled.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
Why is removing the radiator cap from a hot system dangerous?
Steam and boiling water can spray out under pressure
Steam and boiling water under pressure can cause severe burns.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
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 ↗ -
You must add coolant to a system with no recovery or overflow tank. What are the first steps?
Shut the engine off and wait until it has cooled
Switch off the engine and let it cool before touching the cap.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
How should you protect your hands when opening a radiator cap?
Use gloves or a thick cloth
Gloves or a thick cloth protect your hands.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
How should you begin turning the radiator cap?
Slowly to the first stop, which releases the pressure seal
Turn slowly to the first stop, then step back while the pressure is released.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
When may you press down on the radiator cap and turn it further to remove it?
When all pressure has been released
Wait until all the pressure is gone before removing the cap.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
How do you check v-belt tightness?
By pressing on the belts
Learn to check belt tightness on your vehicle by pressing on the belts. Also look for cracks and wear.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
What happens when engine belts are loose?
They do not turn the water pump or fan properly, and the engine overheats
Loose belts slip on the water pump and fan, which leads to overheating.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
What can a coolant hose that breaks while driving lead to?
Engine failure and even fire
Make sure coolant hoses are in good condition, because a broken hose can cause engine failure and fire.
Section 2 · 2.14.1 – Vehicle Checks ↗ -
In very hot weather, what should you know about spots where tar “bleeds” to the road surface?
They are very slippery
Tar rises to the surface in hot weather, and those spots are very slippery.
Section 2 · 2.14.2 – Driving in the Heat ↗ -
Why should you go more slowly in very hot conditions such as the desert?
High speeds create more heat for the tires and engine
Extra heat raises the chance of tire failure, fire and engine failure.
Section 2 · 2.14.2 – Driving in the Heat ↗
Questions and answers by topic
- Licenses, endorsements and tests105
- Disqualifications and state rules110
- Vehicle inspection80
- Basic control and shifting gears47
- Seeing and communicating46
- Controlling your speed62
- Managing space40
- Seeing hazards49
- Distracted and Aggressive Driving71
- Railroad Crossings and Mountain Driving65
- Emergencies, ABS and Skids102
- Accident Procedures and Fires49
- Alcohol, Drugs and Illness41
- Hazardous Materials Rules for All Drivers42
- Transporting Cargo Safely79
- Bus Inspection, Loading and Hazardous Materials74
- Driving a Bus: Stops, Crossings and Prohibited Practices56
- Air Brake Parts: Compressor, Tanks and Foundation Brakes52
- Warnings, Spring Brakes, ABS and Dual Systems59
- Inspecting Air Brake Systems61
- Using Air Brakes51
- Driving Combination Vehicles Safely50
- Combination Vehicle Air Brakes and ABS59
- Coupling and Uncoupling63
- Inspecting a Combination Vehicle24
- Pulling Double and Triple Trailers16
- Coupling, Inspecting and Brake Checks for Doubles34
- Tank Vehicles62
- HazMat basics and who does what48
- Hazard classes, labels and lists64
- Shipping papers and package markings49
- Placards and placard tables40
- Loading and unloading HazMat58
- Bulk packaging and tanks30
- HazMat driving and parking rules72
- HazMat emergencies and reporting60
- Danger zones and mirrors34
- Loading and unloading students47
- Emergency exit and evacuation34
- Railroad-highway crossings40
- Student management, ABS and special situations47