Combination #2
Combination Vehicles Practice Test | District Of Columbia 2026 #2 Page 2 of 3
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.
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8 . When a combination vehicle goes around a corner:
It is acceptable for street signs to be knocked over if they are too close to the road.
When a vehicle goes around a corner, the rear wheels follow a different path than the front wheels. This is called off-tracking. This effect is especially pronounced on vehicles with trailers.
9 . Rollovers happen when:
ABS is working effectively.
Rollovers happen when a vehicle is driven too fast. To reduce the risk of rollover, make sure the weight of cargo is loaded low to the ground, and that you take turns and curves slowly.
10 . Failure to keep the fifth wheel plate properly greased could:
Affect the lights.
Failure to keep the fifth wheel plate properly lubricated can create friction between the tractor and trailer, causing steering problems.
11 . Push in the trailer air supply control to:
Supply the trailer with air.
Push in the trailer air supply control to supply the trailer with air. Pull out the trailer air supply control to turn off the air supply and activate the emergency brakes.
12 . What can the “crack-the-whip” effect do?
Make trucks decelerate.
The "crack-the-whip" effect can cause a trailer to turn over during a lane change. To avoid this phenomenon, drivers should make lane changes at slow, safe speeds.
13 . Having ABS on only one axle:
Will cause extra strain on the other axles.
Having an Anti-Lock Braking System (ABS) on only the trailer, or even on just one axle, will still provide a driver with additional control over the trailer when braking.
14 . When glad hands are coupled, the seals should be pressed together at an angle of:
90 degrees.
When coupling, be sure to couple the proper glad hands. When glad hands are connected, the seals should be pressed together at a 90-degree angle.
2026 District Of Columbia | Frequently Asked Questions
To acquire a CDL Hazmat endorsement in the District of Columbia, you must first hold a valid CDL. Then, pass the Hazardous Materials Knowledge Test at a DMV service location. You'll also need to undergo a federal TSA background check and fingerprinting. Lastly, submit the Hazmat Endorsement Application, proof of U.S. citizenship or legal status, and pay the required fees.
To obtain a CDL Hazmat license, you must already hold a valid Commercial Driver's License (CDL). You also need to pass the Hazardous Materials Knowledge Test, undergo a federal TSA background check, and be fingerprinted. Proof of U.S. citizenship or legal status is required. Lastly, you need to be in good physical health to meet the demands of the job.
When applying for a CDL Hazmat endorsement, you'll need to provide your valid Commercial Driver's License (CDL), proof of U.S. citizenship or legal residency (like a passport or birth certificate), and proof of identity. You'll also need to bring the receipt for your TSA background check and fingerprinting, and complete the Hazmat Endowment Application.
Yes, there is a dedicated written test for the CDL Hazmat endorsement. This test focuses on the rules and safety procedures for handling and transporting hazardous materials. It's essential to study the Hazmat section of your state's CDL manual thoroughly before taking the test to ensure you're well-prepared.
The written test for the CDL Hazmat endorsement covers a range of topics related to hazardous materials. These include identifying hazardous materials, understanding shipping papers, using placards and labels, handling emergencies, loading and unloading procedures, and complying with the relevant safety rules and regulations.
Yes, there are extra charges associated with acquiring a CDL Hazmat endorsement. These include fees for the TSA background check and fingerprinting, which typically cost around $86.50. Additionally, there may be a fee for the endorsement application, which varies by state. It's best to check with your local DMV for specific costs.
Yes, obtaining a CDL Hazmat endorsement requires a mandatory background check and fingerprinting conducted by the Transportation Security Administration (TSA). This ensures the individual doesn't pose a security threat and is part of the federal safety regulations for handling hazardous materials.
Yes, specialized training is mandatory for the CDL Hazmat endorsement. Applicants must pass a written test that covers the regulations and requirements for transporting hazardous materials. After passing the test, they receive a certification, which is the Hazmat endorsement on their Commercial Driver's License (CDL). This ensures they are knowledgeable about handling hazardous materials safely.
No, you cannot legally transport hazardous materials without a valid CDL Hazmat endorsement. This endorsement ensures that you have the necessary knowledge and skills to handle hazardous materials safely. Driving without it can result in serious penalties, including fines and suspension of your commercial driver's license.
Yes, you can add a Hazmat endorsement to your existing CDL. You don't need to apply for a new CDL. However, you must pass a written Hazmat knowledge test, submit to a TSA background check, and pay the associated fees. Once these steps are completed successfully, the Hazmat endorsement will be added to your CDL.