california
CDL Practice Test

This site is designed to help aspiring commercial drivers practice for their State of California Department of Motor Vehicles CDL test. You can take these free California CDL practice tests as many times as you would like. Questions on these tests come from the various commercial driver license topics that are represented in the California CDL handbook. You will be presented with 40 questions and you must answer 34 questions correctly to pass. There is a 50-minute time limit. You may not go back once you answer a question. Click the "Start Test" button below to begin.

1 / 40

Select the part that is not a part of the drum brake:

axle

slack adjuster

brake drum

safety valve

2 / 40

How many different hazard classes are there?

3 / 40

Select the statement that is true in regards to managing space to the sides.

you should always keep your vehicle to the right side of the lane

high gust winds do not cause any issues for triples and doubles

you should try to avoid driving next to others when possible

all answers listed

4 / 40

The Emergency Response Guidebook (ERG):

All of these answers are correct.

Was created by the national department of transportation, so it is used nationwide.

Is studied by emergency personnel to help keep the public safe.

Contains an index of hazardous material id numbers, which is why you must label things correctly.

5 / 40

The bolst, brackets, or bushings that attach the air bag and/or spring to the vehicle and axle frame are _____.

shock dampeners

spring mounts

lug bolt

none of the answers listed

6 / 40

Before backing under the trailer you should______when coupling a tractor and trailer with air lines already connected.

have the trailer brakes off

all answers listed

press down on the brake pedal twice

supply air to the trailer system and then pull the air supply knob out

7 / 40

Which of the following statements about special danger of loading and unloading is true?

Students should be told to leave any dropped objects and move to the point of safety out of danger and get the driver's attention to retrieve the object.

Students should be told not to use the handrails when exiting the bus due to the possibility of causing a clothing hang up.

Students should be told to remain seated while the bus is in motion.

Students should be told to pick up any dropped objects as long as it is not under the bus.

8 / 40

Which of the following is NOT an appropriate reason to flash your braking lights?

to signal to tailgaters that they are too close to your vehicle

to warn vehicles approaching you from behind that you are driving slowly

to alert drivers behind you that there are hazards ahead

to warn drivers behind you when you need to slow down

9 / 40

When approaching railroad tracks, stop your bus:

15 and 50 feet before railroad crossings.

5-10 feet before railroad tracks.

Only if you have manual transmission, then proceed with flashers on.

On the tracks so you can see if the train is coming.

10 / 40

Which of these statements about signaling is correct?

Leave your signal on long after you've changed lanes.

Signaling is a warning, not a request.

Signal to others that it is safe to pass your bus.

Signal your intentions early and continuously.

11 / 40

Charter drivers should not:

Allow riders on the bus until departure time.

Remind riders about rules once trip begins.

Mention rules at the start of the trip.

Explain rules at the start of the trip.

12 / 40

You should back up slowly until____when coupling the trailer.

the tractor comes in contact with the front of the trailer

the cargo inside the trailer shifts

the fifth wheel has just touched the trailer

the rear wheels are visible in the mirror

13 / 40

When using turn signals, which of the following should be avoided?

signal when you want to change lanes

signal when you are merging into traffic

signal before you exit

signal just before you start to make a turn

14 / 40

Do you need to stop before a railroad crossing if you are hauling 100 pounds of Division 4.3 materials?

Only if the arm is down telling vehicles to stop

Impossible to tell without more information

Yes

15 / 40

This gauge will indicate if the generator or alternator is charging:

Coolant

Oil pressure

Gas tank

Voltmeter/ammeter

16 / 40

When should you check your mirrors for a lane change?

After completing the lane change.

All of these answers are correct.

Right after starting the lane change.

Before and after signaling the change.

17 / 40

What is the standee line?

A 2 inch line on the floor that all passengers must stay behind.

A line at the back of the bus where passengers must stand before exiting.

A line around each seat to help each passenger have a little personal space.

A 2 inch line down the aisle to help keep passenger traffic flowing.

18 / 40

The best way to go into a curve is to decrease your speed going into the curve and then ____going through it.

none of the answers listed

ride the brake

slightly accelerate

shift down 2 gears

19 / 40

Should your air compressor stop working:

there will still be air pressure left in the air tanks

there will be no affect to your brakes

the brakes will lock up on you immediately

you will lose your ability to brake immediately

20 / 40

The designation RQ identifies the material's:

Reportable quantity

Reference quotient

Regulatory quantity

Regulatory quotient

21 / 40

You are required to have a tank endorsement when transporting:

Gas or liquid

Passengers

Bulk fertilizer

Materials that are hazardous

22 / 40

A drawbridge does not have a traffic light showing green or a traffic control attendant. How many feet before the draw of a bridge must a bus driver stop?

At least 100 feet.

At least 75 feet.

At least 50 feet.

At least 25 feet.

23 / 40

Select the statement that tells you how you can check the low pressure warning signal.

The low pressure warning signal is only testable by the factory.

Turn the electrical power on and apply pressure on and off the brake pedal to increase air tank pressure. The low air pressure warning signal must come on before the pressure increases to more than 60 psi in the air tank.

Turn the electrical power off and apply pressure on and off the brake pedal to decrease air tank pressure. The low air pressure warning signal must come on before the pressure drops to less than 30 psi in the air tank.

Turn the electrical power on and apply pressure on and off the brake pedal to decrease the air tank pressure. The low air pressure warning signal must come on before the pressure drops to less than 60 psi in the air tank.

24 / 40

Why do air brakes take longer to stop than hydraulic brakes?

longer reaction time

the lines are hotter

it takes more time for the air to flow through the lines

none of the answers listed

25 / 40

A baffled tanker has:

Bulkheads with holes that allow liquid to flow through it.

No side to side surge.

Balls floating in it to increase the speed of the liquid movement.

Separate compartments inside the trailer.

26 / 40

Select the true statement about double or triple trailers.

they can roll over due to abrupt steering movements

they present a rearward amplification hazard

they can have a dangerous "crack the whip" effect

all answers listed

27 / 40

Select the true statement in regards to the braking power of spring brakes.

it will not be affect by the condition of the service brakes

it depends on the adjustment of the service brakes

the braking prower increases when the brakes are hot

braking power can only be tested by licensed mechanics

28 / 40

The minimum tread depth for tires other than the front tires is ____.

2/32

1/32

3/32

4/32

29 / 40

How can you determine if your vehicle is equipped with ABS?

all of these answers are correct

look for wheel speed sensor wires that are coming from the rear of your brakes

check if your vehicle was manufactured after March 1, 1998 (they are required to have the panel light)

check for yellow abs malfunction lamps on the instrument panel

30 / 40

What will happen right away should the service air line come apart but the emergency line is intact while driving a combination vehicle?

the trailer's air tank will leak through the one line

nothing will occur until you try to use the brakes

you will come to a complete stop

the emergency tractor brakes will activate

31 / 40

Urban mass transit coaches may have a brake and accelerator interlock system. Which of the following statements is true?

All of these answers are correct.

The interlock releases when you close the rear door.

The interlock applies the brakes and holds the throttle in idle position when the rear door is open.

Do not use this safety feature in place of the parking brake.

32 / 40

Select the true statement about slack adjusters:

they do not ever need to be adjusted

they can be adjusted automatically or manually

they should only be adjusted by a mechanic that is certified in slack adjusters

they should move a minimum of 2 inches from the push rod attachment

33 / 40

Which of the following is a reason to evacuate the school bus?

The bus abs warning light is on.

The bus is stalled on a rail road track, but there is no train in sight.

A child set off a stink bomb inside the bus.

The bus is stalled on a shoulder of a 4-lane divided highway and it is getting hot inside.

34 / 40

Is it important to look into the back of the fifth wheel to see if the lockpin is locked in?

only every 7 days

only at the end of the shift

yes

35 / 40

Which seats not securely fastened to the bus are usually allowed?

None of these answers are correct.

Window seats.

Any of the last row seats.

The driver's seat only.

36 / 40

When backing, what is the best method to use to avoid blind spots?

use a helper

use mirrors on both sides

back towards the driver's side, where you can see better

look at your path

37 / 40

What is incorrect concerning disruptive passengers?

It may be safer to wait and discharge the disruptive passenger at the next scheduled stop or a well-lighted area where there are other people.

You must ensure the disurptive rider's safety as well as that of others.

You must remove the disruptive passenger immediately for the safety of the others.

Don't discharge such riders where it would be unsafe for them.

38 / 40

Bus drivers must have a commercial driver license if they drive a vehicle designed to seat more than:

15 or more persons, including the driver.

10 or more persons, including the driver.

20 or more persons, excluding the driver.

16 or more persons, including the driver.

39 / 40

Select the factor that is known to cause brakes to fail or fade. (more than one answer may be correct, but select only one)

excessive heat from extensive use

when using the engine brake more than the brakes

brakes that are not aligned properly

tire retread that is mismatched

40 / 40

Which trailer is more likely to roll over when pulling 3 trailers?

the second trailer

the last trailer

the tractor

the first trailer

Your score is

The average score is 65%

5/5 - (2 votes)

CDL Category Practice Tests

CDL Practice Test

How To Get A california Commercial Drivers License

Residents of California may apply for their CDL at the age of 18 years old. These residents may only drive within the California state borders and are not eligible for driving hazmat vehicles. Residents over the age of 21 are eligible for interstate commerce and may receive their Hazmat Certification. All residents must undergo a medical examination by an approved Medical Examiner. The examiner will provide the individual with a Medical Examiner’s Certificate that will show their physical ability to be eligible to operate a commercial vehicle.

Any drivers who falls into the following categories are disqualified from receiving their commercial driver’s license.

Convicted of driving a commercial vehicle impaired in the past two years.
Having multiple driver’s license.
Having a revoked, denied, canceled, or suspended driver’s license.
Being disqualified from obtaining CDL driving privileges in another state.

Applicants for a California CDL must complete a vision test at the time of their application, along with one or more knowledge tests and a practical skills test.

Endorsements
S – School Bus
N – Tank
P – Passenger
H – Hazardous Materials
X – Hazmat and Tank Combination
P – Passenger Vehicle

Hit the Open Road

California CDL License Test Tips

Knowledge tests are required to be passed by all California residents seeking a commercial driver’s license. Class A applicants are required to complete a 70 question assessment regarding both general commercial driving knowledge and combination driving. Class B and C applicants are required to pass a 50 question assessment about general commercial driving knowledge. Those seeking endorsements or the removal of the Air Brake restriction will have to take additional knowledge tests. Each endorsement has a 20 to 30 question assessment based on the topic of the endorsement. All knowledge tests must be passed for the resident to receive their CDL. A passing score is receiving an 80 percent or higher on the assessment. Each applicant is responsible for showcasing their ability to operate a commercial vehicle as part of the CDL skills test. There are three main parts to this test which include the on-road test, pre-trip inspection, and basic control skills test. Applicants must pass all three parts to receive their commercial driver’s license.

Additional Information

Information on the California Department of Motor Vehicles

The State of California Department of Motor Vehicles regulates the certifying and testing of commercial drivers in the California. To get more information contact them via:

Website: https://www.dmv.ca.gov/portal/dmv/detail/commercial/commercial

Phone: 800.777.0133

Additional California CDL Helpful Links

Please use the links below to access more valuable California CDL testing resources and to learn more about practice driving tests for the state of California.

california CDL Practice Test

CDL Category Practice Tests

CDL Practice Test

How To Get A california Commercial Drivers License

Hit the Open Road

California CDL License Test Tips

Additional Information

Information on the California Department of Motor Vehicles

Additional California CDL Helpful Links

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