Combination Vehicles Practice Test | District Of Columbia 2026 #2

Train for FREE online with our District Of Columbia CDL combination vehicle test. The official exam test consists of several obligatory parts, with all of them checking your knowledge of different blocks of road rules. If you need to obtain a DC combination license in 2026, practice as much as possible. Free sample tests published on our website will help you check and improve your knowledge and boost your grades. Please bear in mind that DMV requirements for issuing a combination license may vary from state to state.

Number of Question 20

Passing Score 16

Number of Tests 20

1 . When lightly loaded, combination vehicles:

Should not be driven.

Have reduced braking capabilities.

Will not rollover.

Should be loaded with most of the weight in the rear of the trailer.

When a combination vehicle is lightly loaded, it may have poor traction. It is very easy for wheels to lock up on lightly-loaded vehicles when they are being stopped.

2 . Compared to other commercial motor vehicles, combination vehicles need more space on the road because they are longer and they:

Need more space to turn and stop.

Drive more slowly.

Are twice the width.

Swerve more often.

Combination vehicles need more space on the road than other commercial vehicles because they are longer and need more space to turn and stop. It is especially important to properly manage space when you are operating a combination vehicle.

3 . To prevent a rollover, a driver should:

Keep cargo low.

Place cargo high.

Keep cargo loose.

Turn quickly.

Rollovers can happen when a combination vehicle is turned too quickly. To help prevent the risk of rollover, it is important to keep the vehicle's center of gravity low by loading cargo as close to the ground as possible.

4 . When driving a trailer with ABS, you should:

Not depress the brakes as much as you would when driving a vehicle without ABS.

Use extra braking force to ensure the ABS kicks in.

Brake as you would when driving a vehicle without ABS.

Try to not brakes as often as you would when driving a vehicle without ABS.

When driving a tractor-trailer combination equipped with an Anti-Lock Braking System (ABS), you should brake in the same manner that you would if operating a vehicle without ABS.

5 . If colors are being used to distinguish glad hands, which color is used for service lines?

Orange

Yellow

Green

Blue

When trailer air lines are color-coded, the service lines are generally blue and the emergency lines are generally red.

6 . To help prevent rollovers, you should:

Accelerate quickly after stopping.

Drive slowly around turns.

Keep the load near the back of the trailer.

Keep the load on one side of the trailer.

To lower the risk of a rollover, load your cargo as closely to the ground as possible. To further reduce this risk, take curves and corners slowly.

7 . If a trailer's spring brakes do not release when you push the tractor air supply control, you should:

Check the air line connections.

Release the pintle hook.

Replace the spring brakes.

Drive normally without checking anything.

It is important that all of your vehicle's equipment is in proper working condition before you begin a trip. If a trailer's spring brakes do not release when you push in the tractor air supply control, you should make sure the air line connections are properly attached and sealed.

Study tip:

Reduce your study time from hours to minutes with a DMV exam “Cheat Sheet”

99.2% of people who use the cheat sheet pass the FIRST TIME

Click Here
Full Cheat Sheet

99.2%

99.2% of people who use the cheat sheet pass the FIRST TIME

2026 District Of Columbia | Frequently Asked Questions

To acquire a CDL Passenger endorsement in the District of Columbia, you must first hold a valid CDL. You then need to pass a written passenger endorsement test and a skills test in a vehicle similar to the one you'll be driving. The test covers topics like vehicle inspection, loading/unloading passengers, and emergency procedures.

To obtain a CDL Passenger license in the District of Columbia, an applicant must possess a valid CDL, pass the Passenger Transport written test, complete a Federal Motor Carrier Safety Administration medical examination, and successfully pass a skills test in the type of vehicle similar to the one they will be driving. The applicant must also be at least 21 years old.

Yes, specific training is necessary to earn a CDL Passenger endorsement in the District of Columbia. You must pass a written passenger endorsement test and a skills test in a vehicle similar to the one you'll be driving. While not mandatory, practical experience driving similar vehicles can be beneficial for passing the skills test.

Yes, to secure a CDL Passenger endorsement in the District of Columbia, you are required to pass a written passenger endorsement test. This test covers topics such as vehicle inspection, loading/unloading passengers, and emergency procedures. It is designed to ensure you have the necessary knowledge to safely operate a passenger vehicle.

During the CDL Passenger endorsement skills test, you'll need to demonstrate your ability to safely operate a passenger vehicle. This includes pre-trip vehicle inspection, proper use of mirrors and signals, safe lane changes and turns, proper loading/unloading procedures, and emergency protocol. Your ability to control and maneuver the vehicle in various traffic situations will also be assessed.

No, it is illegal to transport passengers without holding a valid CDL Passenger endorsement in the District of Columbia. A CDL Passenger endorsement is required to operate a commercial vehicle that is designed to transport 16 or more passengers, including the driver. Failure to have the proper endorsement can result in fines and penalties.

Yes, you can add the CDL Passenger endorsement to your existing commercial driver's license. You don't need a new application. However, you must pass the Passenger endorsement written test and a skills test in a passenger vehicle. Remember to bring your current CDL to the DMV when you go for your tests.

Yes, there are specific restrictions for drivers with a CDL Passenger endorsement. For instance, you cannot transport more passengers than your vehicle is designed to carry. Additionally, you are subject to stricter blood alcohol content (BAC) limits and may be disqualified for serious traffic violations or multiple minor violations.

Yes, there are age-related prerequisites and limitations for acquiring the CDL Passenger endorsement in the District of Columbia. To obtain the endorsement, you must be at least 18 years old. However, if you plan to transport passengers across state lines or operate a vehicle with hazardous materials, you must be at least 21 years old. Additionally, certain medical and physical requirements must be met to qualify for the endorsement.

With a CDL Passenger endorsement, you'll be eligible to operate vehicles such as buses, shuttles, or any other vehicle designed to transport 16 or more passengers, including the driver. This includes school buses if you also have a School Bus endorsement. It's important to note that the specific vehicle must match the class of your CDL.