District of Columbia
CDL Practice Test

Simply because the District of Columbia is the only place in the country that has legal taxation without representation doesn't mean there are no laws at all! Every commercial driver in Washington DC must have a valid commercial driver's license. Typically those licenses will be issued in other jurisdictions but Washington DC can and does issue its own. This online exam will help you practice for the District of Columbia CDL Test. 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. Good luck!

1 / 40

Select the action that is not appropriate when driving on slippery roads:

none of the answers listed

use a light pressure on the brake and accelerator pedals

use a speed retarder or engine brake

avoid having traffic in your side space

2 / 40

Overhead inside mirror is used to:

see the area where students exit the bus

see the blind spot immediately behind the bus

monitor traffic that approaches and enters the blind spot area

see all of the students

3 / 40

To decide which placards you need, if any, what three things do you need to know?

Materials hazard class, amount being shipped, and amount of all hazardous materials of all classes on your vehicle.

Packing group numbers, amount being shipped, and amount of all hazardous materials of all classes on your vehicle.

Materials hazard class, location being shipped, and amount of all hazardous materials on your vehicle.

Materials hazard class, percentage of total volume, and amount of all hazardous materials on your vehicle.

4 / 40

A driver of a tank vehicle should take curves, off ramps, and on ramps at a speed lower than the posted speed limit.

True

False

True but only in rainy conditions

True but only in ideal conditions

5 / 40

What kind of surge can occur in a tank with baffles?

Back to front

Bottom to top

All answers listed

Side to side

6 / 40

Under which two special conditions should you downshift?

before starting down a hill and before entering a curve

if there is an accident and in sudden heavy rain

before starting down a hill and before going up a hill

before entering a curve and before going up a hill

7 / 40

When should air tanks be drained?

at every restroom break stop

every 7 days

they don't need to be drained

at the end of each working day

8 / 40

A placarded vehicle must carry what type of fire extinguisher?

One with a rating of 5 b/c minimum.

One with a rating of 10 b/c minimum.

One with a rating of 5 a/b minimum.

One with a rating of 10 a/b minimum.

9 / 40

One reason hauling liquids in tank vehciles require special care is:

Because of uneven expansion.

Because of the extreme weight.

Because of strong winds.

Because of the movement of the liquid.

10 / 40

A hazard class that uses transport indexes to determine the amount that can be loaded in a single vehicle is _____.

Class 7 radioactive materials

Class 1 explosives

Class 3 flammable liquids

Class 6 poisons

11 / 40

In column 1, the "D" symbol means:

Domestic restrictions

Domestic transportation

Devices

Detonators

12 / 40

You should turn off your engine when loading flammable liquid unless:

You are loading at night and need the headlights.

The material does not need a placard.

You are a non-smoker.

You need the engine to run the pump.

13 / 40

When you have a major leak in the service line and put on the brake, the service air pressure will escape and cause the:

the trailer emergency brakes to activate

none of the ansers listed

the trailer tank pressure to decrease

the tractor spring brakes to activate

14 / 40

The parking brakes should be used____in air brake vehicles.

only during post trip inspection

only when parked on an incline

every time the vehicle is parked

as rarely as possible

15 / 40

If you do become sleepy while driving, you should _____.

stop to sleep

turn up the radio

roll down the windows

drink caffeinated beverages

16 / 40

Which of the following are possible causes of tire fires?

poor cargo ventilation or short circuits

improperly loaded cargo and dual tires that touch

loose fuel connections or under-inflated tires

dual tires that touch and under-inflated tires

17 / 40

Select the true statement about what the Air Compressor Governor controls:

it controls when the air compressor pumps air into the storage tanks

it controls when air is released from the storage tank

it controls when the brakes will be applied

it controls when the warning system is activated

18 / 40

Five hazard classes that require placarding in any amount are ______.

explosives 11, corrosive 8, flammable 3, explosives 14, and poison 61

corrosive 4, hazardous 14, flammable 2, explosives 7, and radioactive 12

none of these answers are correct

poison gas 23, dangerous when wet 43, explosives 13, explosives 12, and explosives 11

19 / 40

Within 3 minutes, this gauge pressure should build to 90 psi from 50 psi.

Oil pressure gauge

Coolant pressure gauge

Voltmeter gauge

Air pressure gauge

20 / 40

A commercial motor vehicle (CMV) is defined as:

a vehicle transporting hazardous materials

all of these answers are correct

a vehicle with a gross weight over 26,001 lbs

a vehicle transporting 16 or more passengers

21 / 40

A safe haven is:

A place that has been approved to park unattended vehicles carrying explosives.

A place to stay once you have reported your company for illegal activity.

The slang term for the last stop at the end of your driving day when carrying hazardous materials.

A place where it is safe to dump any kind of hazardous materials.

22 / 40

What are the 3 methods for securing a second trailer before coupling?

all answers listed

parking against another trailer, locking the trailer door, and chocking the tires

chocking the tires, parking on level ground, and charging the air tank

parking on level ground, chocking the tires, and charging the trailer air tank if it doesn't have spring brakes

23 / 40

A safe haven is ______.

an approved place for parking unattended vehicles loaded with corrosive materials

an approved place for parking attended vehicles loaded with flammable materials

an approved place for parking unattended vehicles loaded with radioactive materials

an approved place for parking unattended vehicles loaded with explosive materials

24 / 40

The two other places where the hazardous identification number must appear are:

On a temporary license plate holder and the steering wheel.

On the gas tank and a sticker in the glove compartment.

On the back of the truck and inside the glove compartment.

Any bulk packaging and the cargo tanks.

25 / 40

The emergency air line is used to:

to alert emegency services when there is a problem

engage the tractor's front brake when there is air pressure loss

provide back up air pressure

engage the trailer brakes when there is an air pressure loss

26 / 40

What are the three hazard classes should NOT be loaded into a trailer that has a heater air conditioner unit?

Class 1 explosives, class 3 flammable liquids, and division 21 flammable gas.

Class 1 explosives, class 8 corrosives, and division 5 oxidizers.

Class 2 explosives, class 3 flammable solids, and division 21 inhalation hazard.

None of these answers are correct.

27 / 40

You may use DANGEROUS placards instead of separate placards for each Table 2 hazard class when:

You have not loaded 2,205 pounds or more of any table 2 hazard class material at any one place (you must use the specific placard for this material).

You have 1,001 pounds or more of two or more table 2 hazard classes, requiring different placards.

The correct answer is not listed.

Both of these conditions must be met.

28 / 40

A slack adjuster is:

a lever that connects the brake chamber push rod with the foundation brake camshaft

a lever that connects the brake drum to the brake shoe

a lever that connects the brake camshaft with the brake chamber

a lever that connects the return spring and the brake chamber push rod

29 / 40

You should follow the posted speed limits for curves and be aware of:

A rollover may occur even when driving at the posted speed limit.

The higher center of gravity on a tank truck.

The posted speed limit may be too high for safety.

All answers listed.

30 / 40

Select the two reasons as to why special care is needed when driving a tank vehicle:

None of the answers listed.

The danger of surge and the low center of gravity.

The chance of rollover and of spontaneous combustion.

The danger of surge and the high center of gravity.

31 / 40

Cargo tanks ____.

are large drums temporarily attached to a vehicle

are tanks that the military uses to transport hazardous materials

are bulk packagings permanently attached to a vehicle

are large drums used to contain hazmat that is loaded on a trailer

32 / 40

"Outages" is the word to describe the amount of space required for liquids to expand in as they warm.

False, it's when the vehicle engine fails in some way

False, it's when the vehicle air braking system fails in some way

False, it's when the vehicle power system fails in some way

True

33 / 40

Check that the parking brake will hold by____when the parking brake is engaged and the trailer brakes released if not a combination vehicle.

shifting down to a low gear and trying to pull forward gently

while in neutral increase the rpm to 1500

all answers listed

shift up into a high gear and let off the clutch quickly

34 / 40

The cause of almost half of all truck driver deaths are:

a result of excessive speed

a result of following behind too closely

a result of changing lanes too frequently

a result of rollover

35 / 40

It has just reached freezing. Which of the following areas is slippery?

all of these answers are correct

wet-looking road

a bridge

a shaded area

36 / 40

By law, the warning lights must only be used when approaching a:

Sharp turns.

Any stop the bus makes.

Stop to load or unload students.

Busy intersection.

37 / 40

The container for the mechanism that transforms the steering column action into wheel action is:

Locking pin

Steering linkage

Steering hoses/box

Air brake system

38 / 40

You should___to reduce the air leakage rate.

release the service brake as the engine is running

leave the engine running while charging the air system

release the service brake after turning off the engine

monitor the air pressure gauge as you press on the brake pedal

39 / 40

How do you make sure the trailer height is correct before coupling?

visually check that the rear trailer is lower than the fifth wheel so that the trailer raises slightly when the dolly is pushed under it

you do not need to do a visual check

visually check that they are level height wise

visually check that the lead trailer is higher than the fifth wheel so that the trailer will lower when the dolly is pushed under it

40 / 40

How do you check the air compressor governor "cut in" and "cut out" pressures?

all of these answers are correct

monitor the air pressure gauge

run the engine at a fast idle

decrease the tank pressure by stepping on and off the brake

Your score is

The average score is 0%

5/5 - (1 vote)

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How To Get A District of Columbia Commercial Drivers License

In the District of Columbia, there are classifications of motor vehicles that may only be driven by those with a current commercial drivers license. Additionally, there are four classes of endorsements, including school bus, passenger and tanker. Any vehicle with a gross weight rating over 26,000 pounds is considered commercial in the District of Columbia.

Additional endorsements also include:

Hazardous Materials
Double/Triple Trailer
Tanker
Passenger
School Bus

Requirements to Obtain a District of Columbia CDL:

Have a valid non-commercial driver license
Meet identity, residency, and good driving history eligibility qualifications
Take the applicable CDL knowledge tests
Get a CDL learner permit
Pass the CDL road skills test

A Commercial Driver in Washington DC is held to a higher standard than drivers of typical passenger or other non-commerical vehicles. CDL holders must pass both written tests as well as a practical / skills test. You may practice for the written test using our online CDL test tool above. Upon successful completion, of the official Washington DC CDL skills test, you will be a fully licensed driver and ready to take to the open road!

Hit the Open Road

District of Columbia CDL License Test Tips

You think you're ready? Hold on there, Turbo! Check out these CDL Test Tips before you go zipping to the DMV for your exam!

You must have your CDL learner permit for at least 30 days prior to scheduling your road skills test.
Make an appointment on the DC Online Road Test Appointment Scheduler. Make sure to have your driver license number handy...you'll need it.
On your test day, arrive 15 minutes early. You will need to bring a CDL licensed driver aged 21 or older and this person must hold the CDL class and endorsements you are testing for.

You'll need to bring a few other things with you as well.

valid CDL learner permit
valid NCDL
DOT medical certification card
an appropriate vehicle in which to complete your CDL test
current registration and insurance for the vehicle

If you fail the CDL test you must wait three calendar days before attempting it again. If you fail a second time, you cannot re-test for ninety days!

Additional Information

Information on the Washington DC Department of Motor Vehicles

The District of Columbia CDL certifying agency is responsible for testing and certifying all commercial drivers. To get more information contact them via:

Website: https://dmv.dc.gov/service/obtain-commercial-driver-license
Phone: 202.673.6813
Email: [email protected]

Additional Washington DC CDL Helpful Links

Please use the links below to learn more about helpful topics related to the District of Columbia CDL testing program or other CDL-related topics.

District of Columbia CDL Practice Test

District of Columbia Drivers Test

District of Columbia Motorcycle Test

District of Columbia CDL Test

CDL Category Practice Tests

CDL Practice Test

How To Get A District of Columbia Commercial Drivers License

Hit the Open Road

District of Columbia CDL License Test Tips

Additional Information

Information on the Washington DC Department of Motor Vehicles

Additional Washington DC CDL Helpful Links

District of Columbia
CDL Practice Test