CA DMV CDL General Knowledge Questions

Which of these is not a good thing to remember about drinking alcohol?

A) The driver can control how fast the body gets rid of alcohol
B) Small quantities of alcohol improve reaction time
C) Alcohol first affects judgement and self control

Which of these is not a good rule to follow when caring for an injured person at a collision 

A) If a qualified person is helping them, stay out of the way unless asked to assist
B) Move severely injured persons if a danger exists
C) Keep injured persons cool

Which of these statements is true about medicines used to treat the common cold 

A) It can be used while driving if you only take half the regular dosage 
B) It should only be used when driving in daytime 
C) If often makes you sleepy and this should not be used while driving

The total weight of the powered unit, The trailer, and the cargo is called :

A) Gross vehicle weight
B) Gross combination weight
C) Gross axle weight

Which piece of emergency equipment should be in your vehicle ?

A) Circuit breakers
B) First aid kit 
C) Warning devices for parked vehicles

Which of these statements is true about causes of vehicle fires ?

A) Under-inflated tires will NOT cause a vehicle
B) Carrying a properly charged fire extinguisher will help prevent fires 
C) Poor trailer ventilation can cause flammable cargo to catch on fire

Brake "fade" can be: 

A) Caused by the brakes getting very hot 
B) Corrected by letting up on the brakes for 1-2 seconds and then reapplying them 
C) Caused by very cold weather

Which of these statements is true about vehicle fires ?

A) If the cargo or box trailer catches on fire, open the doors as soon as you can 
B) If your engine is on fire, open the hood as soon as you can 
C) A burning tire should be cooled with water

Which of these statements is true about brakes?

A) Brakes absorb more heat to stop heavier vehicles 
B) Brake drums cool very quickly when the vehicle is moving very fast 
C) Brake fade is not caused by heat

Which of the following does not provide extra Gears on some trucks ?

A) Automatic transmissions 
B) Auxiliary transmissions
C) Multi-speed rear axles

You are starting you vehicle in motion from stop. As you apply power to the drive wheels, they start to spin. You should :

A) Take your foot off the accelerator 
B) take your foot off the accelerator and apply the brakes 
C) try a lower gear

You wish to turn right from a two lane, Two -way street into another .Your vehicle is so long that you vehicle is so long that you must swing wide to complete the turn . Which of these figures shower how you

A) Figure A 
B) Figure B
C) Figure C

Which of these statements is true about downshifting ?

A) Downshift before you enter the curve 
B) Let the rpm's decrease while the clutch is released and the shift lever is in neutral 
C) Downshift just after you enter the curve

Which of these is NOT a danger when an automatic transmission is forced into a lower gear at high speed?

A) Damage to the transmission
B) Loss of engine breaking effect 
C) Loss of steering control

Which of these statements is true about backing a heavy vehicle?

A) You should avoid backing whenever you can 
B) Helpers should be out of sight and use only voice (spoken) signals to communicate with the driver 
C) It's safer to back towards the right side of the vehicle

The distance that you should look ahead of your vehicle while driving is about ____ mile at highway speeds 

A) 1/8 
B) 1/4
C) 1/2

The distance that you should look ahead of your vehicle while driving is ______ at low speeds 
A) 1/2 block 
B) 1 block 
C) 2 blocks

The Commercial Driver Handbook suggests several things to do when you pass a vehicle. Which of these is NOT one of them?

A) Lightly tap your horn, if needed 
B) At night, turn on your high beams while you pass the vehicle 
C) Assume the other driver does not see you

Use your vehicles horn when: 

A) A car is in your way 
B) It may help avoid a crash
C) You want to change lanes

Which of these statements is true about speed management ?


A) Shady parts of the road allow better traction than open areas
B) Road surfaces will freeze before bridges 
C) On slippery road, it takes longer to stop and is harder to turn without skidding

Your driving a heavy vehicle. You must exit a highway using an off ramp that curves downhill. You should: 

A) Slow down to a safe speed before the curve 
B) Slow to the posted speed limit for the off ramp 
C) Wait until you are in the curve before downshifting

You are driving a 40-foot vehicle at 35 m.p.h. miles per hour the road is dry and visibility is good . What is the least amount of seconds in space that you should keep in front of your vehicle to be safe ?
A) 3 seconds 
B) 4 seconds 
C) 5 seconds

If someone is following you to closely ( tailgating ) , you should : 

A) Flash you break lights 
B) Increase you following distance 
C) Signal the tailgater when it is safe to pass you

Which of these is a good thing to do when driving at night?

A) Drive slowly enough to stop within the range of your headlights
B) Look directly at oncoming headlights only briefly
C) Keep your instrument lights bright

Which of these is NOT something you should do if your headlights are not working properly?

A) Leave your high beams on
B) Clean the headlights
C) Adjust the headlights

When the roads are slippery, you should:

A) Make turns as carefully as possible
B) Stop and test the traction while going up hills
C) Decrease the distance that you look ahead of your vehicle

You should avoid driving through deep puddles or flowing water. But, If you could not, which of these steps can help keep your brakes working?

A) Pressing both the brake pedals and accelerators firmly after coming out of the water
B) Gently putting on the brakes while driving through the water
C) Turning on your brake heaters

Which of these is true about the radiator shutters and the winter front?

A) The winter front should be closed tightly
B) You should remove ice from the radiator shutters 
C) The engine may overheat if the winter front is left open

Which of these statements is NOT true about engine belts in hot weather?

A) Cracking is likely to occur but is not a safety threat
B) You can check the tightness of the belts by pressing on them
C) Loose belts will not turn the water pump and/or fan on properly

You can see this sign on a vehicle ahead of you. What does this sign mean?

A) Slow-moving vehicle
B) Hazardous materials on board
C) Student driver

What should you do when you see a hazard in the roadway?

A) Swerve around it and get back in your lane
B) Stop quickly and pull to the side of the road
C) Use your 4-way flasher or brake lights to warn others

A car suddenly "cut" in front of you creating a hazard. Which of these actions should you NOT take?

A) Honk and stay close behind the car
B) Slow down to prevent a crash
C) Signal and change lanes to avoid the car if possible

Truck escape ramps:

A) Help avoid damage to vehicles
B) Can not be used by certain types of heavy vehicles
C) Are not for buses

Which of these statements is a good rule to remember when your vehicle is in a traffic emergency and may collide with another vehicle:

A) You can almost always turn to an obstacle more quickly than you can stop
B) Stopping is always the safest action in a traffic emergency
C) Leaving the road is always more risky in a traffic emergancy

Your vehicle has hydraulic brakes.While traveling on a level road,you press the break peddle and find that it goes to the floor .which of these statements is true ?

A) The parking break will not work because it is part of the same hydraulic system 
B) Pumping the break will generate enough presser to stop the vehicle 
C) Shifting into neutral will help slow the vehicle

Hydroplaning : 

A) Occurs when there is a lot of water 
B) Cannot occur when driving through a puddle 
C) Is more likely if the tire presser is low

Most serious skids result from:

A) Turning to sharply 
B) Having an even load 
C) Driving to fast for conditions

Which of these statements is true about cargo loading ? 

A) Legal allowed by a state is considered safe for all driving conditions
B) State laws dictate legal weight limits 
C) If cargo is loaded by shipper, the driver is not responsible for overloading

Bridge formulas permit : 

A) Less maximum weight for axles that are close together 
B) Less maximum axle weight for axles that are far apart 
C) The same maximum axles weight for any axle spacing

Which of these statements is true about tires?

A) You should inspect your tires every 2 hours or every hundred miles when driving in very hot weather
B) The air pressure of a tire decreases as the temperature of the tire increases
C) If the tires are too hot to touch, release 5-10 pounds of air pressure to cool them down

You are checking your steering and exhaust systems in the pre-trip inspection. Which of these problems should be fixed before the vehicle is driven?

A) Oil on the tie rod
B) Grey smoke from the exhaust pipe
C) Steering wheel play-more than 10% (2 inches on a 20 inch wheel)

Which of these items is NOT checked in a pre-trip inspections?

A) Whether all vehicle lights are working and clean
B) Cargo securement 
C) Amount of fuel in the vehicle

Which of these statements is true about shipping hazardous materials?

A) Four-inch, circular, red hazardous material label must be on the container
B) Gas cylinders that will not hold a label must be shipped undercover
C) A four-inch, diamond-shaped, hazardous materials label must be on the container

One can recognize hazardous materials by looking at the containers:

A) Label
B) Shape
C) Color

You must stop on a hill or curve on a two-lane, two-way road. How far back should you place your reflective triangles?

A) Within 250 feet of the vehicle
B) Within 500 feet behind the vehicle
C) As far back as necessary, so others can see your vehicle

You are driving a new truck with a manual transmission. What gear will you probably have to use to take a long, steep downhill grade?

A) The same gear than you would use to climb the hill
B) A lower gear than you would use to climb the hill 
C) A higher gear than you would use to climb the hill

To help you stay alert while driving, you should:

A) Take short breaks before you are drowsy 
B) Schedule trips for hours that you are normally asleep 
C) Keep the cab warm and quiet

Which of these is true about hours of service ?

A) You must take a break after every 2 hours of driving 
B) After 1,000 hours of service you will be exempt from certain regulation 
C) You should balance your hours of service with enough sleep to keep you alert

Which of the following is true about preventing fatigue on a long trip ?

A) Stop periodically for the rest and exercise 
B) Keep the vehicle closed and heated 
C) Take an over-the counter stimulant

The best time to take a short break is: 

A) Before you  feel drowsy or tired 
B) Immediately after yawning several times 
C) Immediately after you have drifted off the road

As blood alcohol concentration (BAC)Goes up , what happens?

A) The drinker can clearly see how alcohol is affecting him/her
B) The effects of alcohol decrease 
C) Judgement and self control are effected

Which of these statements is true regarding the use of drugs while driving ? 

A) Prescription drugs are allowed if a doctor says the drugs will not affect safe driving ability 
B) No prescription or non-prescription drugs are allowed at any time, for any reason
C) Use of amphetamines like "speed" if you are using the drug to stay awake

You will be place out-of service for 24 hours if you blood alcohol concentration (BAC) is :

A) At least .02%
B) At least .04%
C) Any detectable amount below .04%

Which of these statements is NOT true ? 

A) Alcohol goes directly from the stomach to the blood stream 
B) A drinker can control how fast his or her body absorbs and gets rid of alcohol 
C) BAC is determined by how fast you drink, how much you drink, and how much you weight

On which fires can you use water ?

A) Tire
B) Gasoline
C) Electrial

Which of these statements is true about warning other drivers of a stopped vehicle?

A) Move the rear reflective triangle back if the driver's vision is obscured within 500 feet 
B) Keep the vehicle's taillights on to warn other drivers
C) Put out your emergency warning device before within 5 minutes

Which of these statements is true about engine overheating ?

A) Never shut off an overheated engine until it cools
B) Never remove the radiator cap on a pressurized system until the system has cooled
C) Antifreeze is not needed when the weather is warm

For your safety, when you place your reflective triangles you should:

A) Carry the triangles at your side 
B) Hold the triangles with the reflective side toward the oncoming traffic
C) Keep them out of sight while walking to the locations where you will place them

Retarders:

A)Allow you to disconnect the steering axle brakes
B) Can cause the drive wheels to skid when they poor traction
C) Can not be used on interstate highways

Which of the following is not a type of retarder?

A) Electric 
B) Hydraulic
C) Robotic

What is the proper way to hold a steering wheel ?

A) Both hands together, near the top of the wheel 
B) Both hands together, Near the bottom of the wheel
C) Both hands, on opposite sides of the wheel

You are driving a long vehicle that makes wide turns. You want to make a left turn from Elm street onto oak street. There are two left turn lane ( marked"A" and "B") ON Elm street, and Oak street is four lane streets with two lanes i each direction .You should :

A) Use left turn lane "A" 
B) Use left turn lane "B"
C) Start in left turn lane "A" And swing into left turn lane "B" Just before entering the intersection

Which of these statements is true about double-clutching and shifting ?

A) Double-clutching should only be used with a heavy load
B) Double-clutching should not be used when the road is slippery
C) You can use the tachometer to tell you when to shift

If you have a heavy load that is slowing you down on an upgrade, you should: 

A) Shift into a lower gear 
B) Exit the road until traffic is lighter
C) Drive on the shoulder so others can pass easily

Which of these statements is NOT true about backing a heavy vehicle ?
A) You should back and turn toward the driver's side whenever possible
B) You should use a helper and communicate with hand signals
C) You should back slowly until you sightly bump into the dock

How far should a driver look ahead of vehicle while driving ?

A) 1-2 seconds
B)5-8 seconds
C) 12-15 seconds

In your mirror, you see a car approaching from the rear. The next time you check your mirror, you don't see the car. To change lanes, you should:

A) Wait until you are sure the car isn't in your blind spot
B) Ease into the other lane slowly so the car can get out of the way
C) Assume the car left the road and changed lanes as normal

According to the Commercial Driver Handbook, why should you limit the use of your horn?

A) It can startle other drivers
B) It reduces air pressure needed to stop vehicle with air brakes
C) You should keep both hands on the steering wheel at all times

Which of these statements is the proper way to signal for a lane change?

A) Signal just as you begin to change lanes, and drift over slowly
B) Signal early and change lanes slowly and smoothly
C) Signal before you change lanes, and then move forward quickly

You are driving a heavy vehicle at 35 mph. The speed limit is 55 mph. the safest speed for your vehicle is:

A) 25 mph
B) 35 mph
C) 45 mph

Whenever you double your speed, it will take about ____ times as much distance to stop.

A) Two
B) Three
C) Four

You are driving a vehicle at 55 mph on dry pavement. About how much total stopping distance will you need to bring it to a stop?

A) Twice the length of the vehicle
B) Half the length of a football field
C)The length of a football field

Which of these statements is true about overhead clearance?

A) You should assume posted clearance signs are correct
B) The weight of the vehicle changes its height
C) If the road surface causes your vehicle to tilt toward the edge of the road, you should drive close to the shoulder

When driving at night you should:

A) Look to the left side of the road when a vehicle is driving towards you
B) Adjust your speed to keep your stopping distance within your sight distance
C) Dim your lights within 300 feet of an oncoming vehicle

What should you do if a car coming toward you at night keeps its high beams on?

A) Flash your high beams at the other driver
B) Look to the right edge of your lane or the right side of the road
C) Slow down and look straight ahead in your lane

The road you are driving becomes very slippery due to ice. Which of these is a good thing to do?

A) Stop driving as soon as you can safely do so 
B) Downshift to stop
C) Keep varying your speed by accelerating and braking

Which of these statements is true about cold-weather driving?

A) An engine cannot overheat when the weather is very cold
B) Windshield washer antifreeze should be used
C) Exhaust system leaks are less dangerous in cold weather

Which of these is especially true about your tires in hot weather?

A) You should check tire mounting and air pressure before driving
B) If a tire is too hot to the touch, you should hose it down with water
C) A small amount of air should be let out sot the air pressure remains steady

Which of these statements is true about bad weather driving conditions?

A) When the temperature drop, bridges will freeze before roads
B) The road is more slippery as rain contues than when rain begins
C) Driving conditions become more dangerous as the temperature rises

When driving through roadway work zones, you should:

A) Reduce speed only if workers are close to roadway
B) Turn on your parking lights
C) Watch for sharp pavement drop-offs

Which of these statements is true about other drivers?

A) Mail or delivery truck drivers do not pose a hazard
B) Drivers using turn signals can be trusted to turn in the direction they indicate
C) Short-term or daily rental truck drivers are often not used to the limited vision and pose a hazard

When you must leave the road to avoid a hazard or emergency, you should keep in mind that:

A) Most shoulders are not strong enough to support the weight of a large vehicle
B) It is less dangerous to drive onto the shoulder than to risk a collision
C) You may be unable to re-enter the road

What should you do when your vehicle hydroplanes?

A) Start stab braking
B) Release the accelerator
C) Accelerate slightly

Which of these is important to remember about emergency braking?

A) Disconnecting the steering axle brakes will help keep your vehicle in a straight line
B) If the wheels are skidding, you cannot control the vehicle
C) Never do it without downshifting first

Which of these is a good thing to do when you steer to avoid a crash