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

The reason a bulk liquid tanker is hard to handle is:

Because of the high friction point.

Because the cargo has a high center of gravity.

Because the cargo has a low center of gravity.

Because the cargo has a high density.

2 / 40

What is the brake system that applies and releases the brakes when the brake pedal is used?

engine brake system

service brake system

lock brake system

none of the answers listed

3 / 40

Animals and human foodstuffs should not be loaded in the same vehicle with?

Poisons

Flammable liquids

Explosives

Flammable gases

4 / 40

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

Gas tank

Coolant

Oil pressure

Voltmeter/ammeter

5 / 40

When transporting hazardous loads, you must check the tires at least:

Twice every day.

Every six hours.

Every 200 miles.

Every two hours or 100 miles.

6 / 40

Which of the following statements about the bus interior is false?

If you use your outside lights, you don't need to turn on red emergency door light.

The seats must be safe for riders all seats must be securely fastened to the bus.

Never drive with an open emergency exit door or window.

If there is a red emergency door light, it must work.

7 / 40

You should check the_____when loading small tanks equipped with bulkheads.

distribution of the weight

expansion rate

fuel to air ratio

percentage of water

8 / 40

This carries hydraulic fluid or air to the wheel brake assemby.

Brake drums

Slack pieces

Connector rods

Brake lines/hoses

9 / 40

Why should you test the tractor protection valve?

to avoid the emergency brakes kicking on due to loss of air

to avoid loss of air from the trailer brakes

all answers listed

to avoid loss of air from the air hose

10 / 40

Which trailer is most likely to tip over due to the crack the whip effect?

the first trailer of a triples

the heaviest trailer

the last trailer of a triple

the last trailer of a double

11 / 40

Do you need to stop before a railroad crossing if you are hauling 100 pounds of Division 4.3 Dangerous When Wet material?

Only in populated areas

Yes

Only if you have more than 1,001 pounds of it

12 / 40

What is the reason that placards are used?

it is the law

communicate the risk

to prevent terrorism

so hazmat is not mixed with food

13 / 40

What is NOT one of the four skill areas that operating a commercial vehicle requires?

first aid certification

safely backing

accelerating

steering

14 / 40

Your engine runs a pump when you are delivering compressed gas. Should you turn off your engine before or after you unhook the hoses after finishing that delivery?

Turn it off on arrival—use other power to run the pump.

Turn it off before unhooking.

Leave it on the entire time.

Turn if off after unhooking.

15 / 40

What will occur if you cross the connect the air lines?

the tractor brakes will lock up

the tractor will not be able to move

there will not be air going to the trailer brakes

nothing will occur, it'll funciton as normal

16 / 40

You must keep shipping papers describing hazardous materials ______.

in a pouch on the driver’s door or in clear view within immediate reach while the seat belt is fastened while driving on the driver’s seat when out of the vehicle

in a pouch on the drivers door or in the overhead compartment above the driver’s seat only

with the bills of lading

within 100 feet of the hazardous materials at all times

17 / 40

The front trailer supports should be____before driving away.

3 turns down from the top and the crank handle secured in its bracket

raised 1/2 way with the crank handle secured in its bracket

raised fully and the crank handle secured in its bracket

raised 1/3 of the way with the crank handle secured in its bracket

18 / 40

Select the inappropriate way to test for the low pressure warning signal.

turn off the engine

decreased the air pressure by stepping on and off the brake pedal

ask for a pedestrian to listen for the signal

have the electrical power on

19 / 40

The brake pushrod should not move more than____for manual slack adjusters.

checking is not required in vehicles built after 1994 as they have automatic slack adjusters

an inch when pulled by hand with the brakes released

movement is not allowed

1-2 inches while the brakes are set

20 / 40

It is important for driving safety to always be looking ahead. Which of the following is NOT a recommended time/distance that you should be looking ahead?

about 1 block for city driving

about 12-15 seconds

about 1/4 mile for open highway driving

about 5 car lengths on the highway

21 / 40

It takes special care to drive tankers with liquid in them because:

The high center of gravity of the load.

The movement of the liquid even when the truck is stopped.

The baffles create odd rocking motions.

The low center of gravity of the load.

22 / 40

What is the first thing to do if your vehicle catches fire while driving?

open the door and jump out of the vehicle

find a service station to pull into

open the hood and let the flames die down

pull off the road and park in an open area

23 / 40

How do you supply air to the trailer tanks?

by pulling out the trailer air supply valve

by pushing in the trailer air supply valve

by connecting the service line glad hand

by connecting the red and blue lines

24 / 40

To avoid rollover when going through a curve, the best thing to do is:

Drive at a speed below the posted speed limit.

Drive at a speed higher than the posted speed limit.

Pump the brakes through the curve.

Ride the brakes through the curve.

25 / 40

You should expect____when backing a tractor under a trailer.

the trailer to lift slightly

the trailer to be completely still

the end of the kingpin to be level with the top of the fifth wheel

the trailer landing gear to be fully extended

26 / 40

Which signals may be used to warn of a stopped vehicle that contains explosives?

Flares or fuses

Reflective triangles

All of these answers are correct

Signal fires

27 / 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 but only in ideal conditions

True

False

True but only in rainy conditions

28 / 40

Which of the following are possible causes of tire fires?

dual tires that touch and under-inflated tires

poor cargo ventilation or short circuits

loose fuel connections or under-inflated tires

improperly loaded cargo and dual tires that touch

29 / 40

While completing the 1st component of the air brake check you are required to fully push down on the foot brake and _____.

none of the answers listed

see if the air pressure drops more than 4 lbs in a minute while holding it down for a full minute in a combination vehicle

both of the answers listed

see if the air pressure drops more than 3 lbs in a minute while holding it down for that full minute in a single vehicle

30 / 40

Where can you find a shipper’s certification?

It is a separate document that all hazmat drivers must keep in their vehicles.

There is no such thing.

On the original shipping paper.

On all packages.

31 / 40

Select the factors that can cause your brakes to fade or fail:

the brakes are out of adjustment

all of these answers are correct

using the service brakes excessively

not relying on engine braking enough

32 / 40

How far away are you required to park from a bridge, tunnel, or building if you are carrying Division 1.2 or 1.3 materials?

At least 500 feet

At least 600 feet

At least 400 feet

At least 300 feet

33 / 40

The safety catch for the fifth wheel locking lever must be ____ for a coupling to be complete.

above the locking lever

threaded through the locking lever

sticking straight up

below the locking lever

34 / 40

As the driver of a bus, how can you best avoid hindering other traffic on the highway?

By passing only the slowest vehicles.

By never passing.

By driving faster than the other traffic.

By staying in the right lane if you can.

35 / 40

When should the trailer hand valve be used?

to test the trailer brakes

all answers listed

when parked in a service lot

when driving at highway speeds

36 / 40

After the initial drop, the maximum leakage rates per minute is:

4 psi for a combination vehicle and 3 psi for a single vehicle

6 psi for a combination vehicle and 5 psi for single vehicle

3 psi for combination vehicle and 1 psi for single vehicle

10 psi for combination vehicle and 5 psi for single vehicle

37 / 40

To prevent a roll over a driver can 1) keep the cargo as low to the ground as possible and 2) _____.

have the brakes properly adjusted

take turns slowly

have the fifth wheel's free play as tight as possible

drive while intoxicated

38 / 40

The parking brakes should be used____in air brake vehicles.

only during post trip inspection

as rarely as possible

every time the vehicle is parked

only when parked on an incline

39 / 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 emergency tractor brakes will activate

nothing will occur until you try to use the brakes

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

you will come to a complete stop

40 / 40

If you are hauling hazardous materials and have ___ tires on your vehicle, you must stop and check them every time you park.

radial

dual

treaded

bias

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