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 3 parts of the air brake system are: service brakes, parking brakes, and ____.

bolt brakes

v-cam brakes

foot brakes

disc brakes

2 / 40

You should look into the back of the fifth wheel on a dolly to see if it is locked onto the kingpin.

false

true

only at the end of a shift

only in a level loading dock

3 / 40

How often should you check the cargo you are transporting?

all of these answers are correct

after every break you take during driving

within the first 50 miles after beginning a trip

every 150 miles or every three hours

4 / 40

Where can you find a shipper’s certification?

On the original shipping paper.

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

On all packages.

There is no such thing.

5 / 40

Select the true statement:

you should always ride the brakes

a bobtail tractor will take longer to stop than a combination vehicle that is loaded to the max

light vehicles require more braking power than heavier vehicles

wait to brake heavy vehicles for as long as you can

6 / 40

What is the best way to prevent brakes form overheating while drive down a steep grade?

use the trailer brakes only

use countersteering practices

drive at a speed of 5 mph below your safe speed

use the stab braking method

7 / 40

This object should not move more than an inch by pulled by hand with the brakes released for manual slack adjusters.

The brake pushrod

The air lines

The bounce absorbers

The brake chambers

8 / 40

Operating a motor vehicle with the intent of doing harm to others or physically assaulting a driver or their vehicle is known as?

tailgating

road rage

defensive driving

aggressive driving

9 / 40

The correct trailer height when coupling the rear trailer is:

there is 5 inches of space between the lower and upper fifth wheel

slightly lower than the center of the fifth wheel

the kingpin is touching the fifth wheel

when the locking jaws are open around the kingpin

10 / 40

An emergency escape ramp should be used _____.

any time the truck experiences a significant loss of braking power

only in ideal conditions

only when not carrying a load

only when it is raining

11 / 40

What should you do if you start a trailer skid?

quickly step on the brakes

release the brakes to get traction back

slowly apply a firm pressure to the brakes

use your trailer hand brake

12 / 40

Select what you should not do when coupling the glad hands.

make sure to match the colors or check the tags before connecting

press the seals together at a 90 degree angle

clean the couplers before connecting them

cross the air supply lines to test for leaks

13 / 40

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

movement is not allowed

an inch when pulled by hand with the brakes released

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

1-2 inches while the brakes are set

14 / 40

When stopped on a divided highway where should your reflectors be placed?

10 feet, 100 feet, and 200 feet toward the approaching traffic

20 feet, 150 feet, and 300 feet toward the approaching traffic

15 feet, 75 feet, and 150 feet toward the approaching traffic

30 feet, 100 feet, and 150 feet toward the approaching traffic

15 / 40

When driving with multiple trailers, which one should be right behind the tractor?

the trailer with the heaviest load

the trailer longest in length

the trailer with the smallest road

the trailers shortest in length

16 / 40

What does the amount of liquid you can carry depend on?

The outage of the liquid.

The material the baffles are made from.

The vehicle's horsepower rating.

The center of gravity.

17 / 40

What handling effect will baffles have?

There will be less of surging front to back.

There will be an increase in slow surge.

None of the answers listed.

There will be less side to side surging.

18 / 40

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

pull off the road and park in an open area

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

19 / 40

Which of the following is a recommended procedure when unloading the students?

Let the students begin moving to the front of the bus before it's fully stopped to maximize efficiency.

Position yourself outside of the bus in front of crossover mirror to supervise unloading.

Tell students to remain seated until they are told to exit.

Put the transmission in neutral gear and put on the brakes.

20 / 40

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

Voltmeter/ammeter

Oil pressure

Gas tank

Coolant

21 / 40

Signs of distracted drivers include:

individuals listening to music too loudly

drivers having conversations with passengers

individuals driving at a consistent speed above the speed limit

vehicles exiting the roadway

22 / 40

You should activate hazard lights within approximately how many feet before railroad crossing?

300 feet

250 feet

200 feet

400 feet

23 / 40

Select the true statement in regards to stopping distance and speed:

Larger / heavier vehicles generally take longer to stop.

A wet road will double the stopping distance at any speed.

All answers listed.

You require 4 times as much stopping distance when driving at 40 mph compared to 20 mph.

24 / 40

In what position should shut off valves on the rear of the last trailer be in on a set of double trailers?

in a closed position

in a closed position for the rear trailer and an open position for the front trailers

in an open position

in an open position for the rear trailer and a closed position for the front trailer

25 / 40

What color and shape is the trailer air supply control?

it is a square knob that is yellow

it is a triangle-shaped knob that is red

it is a square knob that is red

it is an 8-sided knob that is red

26 / 40

Which of the following parts do not get checked in the Bus Interior inspection:

Emergency exit handles.

Signaling devices, including the restroom emergency buzzer, if the bus has a restroom.

Each hand-hold and railing.

Seat coverings.

27 / 40

The air leakage rate for a combination vehicle should not exceed ____psi a minute.

28 / 40

When accelerating:

do not engage the clutch before you take your foot off the brake

speed up smoothly and gradually and avoid jerking

always use the parking brake to slow down

"hammer down" when your wheels start to spin

29 / 40

Which of the following is a clue another driver is impaired:

Open window in warm weather.

Exiting the interstate when there's no gas station visible.

Stopping at a green light, or waiting too long at a stop.

All of these answers are correct.

30 / 40

If hazardous material is spilling from your vehicle, do not move your vehicle:

In an upwind direction.

Any more than 500 feet.

Any more that 450 feet.

Any more than safety required.

31 / 40

Select the statement that is true in regards to quick steering movements and triple/double trailers:

it is easier to countersteer compared to other vehicles

as you perform quick steering movements you should apply pressure to the brake pedal

they flip over due to quick steering movements a lot easier than other vehicles

there are no issues that occur from quick steering

32 / 40

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

the last trailer of a double

the last trailer of a triple

the heaviest trailer

the first trailer of a triples

33 / 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 400 feet

At least 300 feet

At least 500 feet

At least 600 feet

34 / 40

You must first______to supply air to the trailer.

turn off the engine so you can hear the brakes

push in the tractor protection valve

cross the air lines to check for the presence of leaks

pull out the tractor protection valve

35 / 40

Select the true statement in regards to large combination vehicles taking longer to stop.

they take longer to stop than bobtail tractors

they take the same amount of time to stop when empty or loaded

they take longer to stop when they are empty

they take longer to stop when loaded down

36 / 40

The most important hand signal you should agree on with a helper is:

“turn up the music”

“stop”

“faster”

“go”

37 / 40

How do you check the connection after locking the kingpin into the fifth wheel?

pull forward 25 feet, turn to the left, and then to the right

pull forward 25 feet, turn to the right, and then to the left

pull the tractor ahead gently with the trailer brakes locked down

pull the tractor at a sharp right to release the trailer brakes

38 / 40

You should make sure the_____before backing under a trailer.

landing gear is fully raised

tractor shut off valve is normal

air brakes have been shut off

trailer brakes are locked down

39 / 40

Which of the following is NOT an important reason to look far ahead when you are driving?

look for vehicles coming into your lane

look for brake lights from slowing vehicles

determine if there are any upcoming traffic lights that might require you to stop

determine if there are any hills coming up

40 / 40

How do you secure a second trailer to your combination vehicle?

use the emergency air brakes or the trailer's spring brakes only

use wheel chocks only

use emergency air brakes, spring brakes, and wheel chocks together

none of the answers listed

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