Knowledge Test Class A #1
Class A Driving Test | District Of Columbia 2026 #1 Page 6 of 7
Train for FREE online with our District Of Columbia class A license 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 CDL class A permit 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 CDL class A requirements may vary from state to state.
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36 . A one-way check valve:
Holds the spring brakes in position until they are used.
A one-way check valve is required to be between an air compressor and the first main reservoir. This valve prevents air from escaping the system if the air compressor develops a leak.
37 . Laws about securing loads and regulating CMV weights may vary from state to state. During interstate travel:
The driver can choose which state’s laws to follow.
Commercial vehicle weight, securement of cargo, covering of loads, and where large vehicles can be driven are all regulated by federal, state, and local laws. These vary from place to place, so you must be aware of the rules that apply where you will be driving. State laws in the state in which you are driving take precedence.
38 . Off-ramps:
Should be used only if following another vehicle.
The combination of slopes and curves can make freeway on- and off-ramps dangerous for trucks. Remember that posted speed limits on ramps may be safe to be driven by cars but too fast to be driven by large or heavily-loaded vehicles.
39 . Tie-downs are used to:
Label radioactive materials.
On flatbed trailers and trailers without sides, cargo must be tied down to prevent it from shifting or falling in transit. There should be at least one tie-down for every 10 feet of cargo. Regardless of the size of the cargo, at least two tie-downs must be used.
40 . When inspecting the engine compartment, you should not:
Check the windshield washer fluid level.
When inspecting the engine compartment, you should check the oil level, coolant level, and windshield washer fluid level, among other things.
41 . When a construction worker is close to the road, you should:
Wait until the construction is complete before proceeding.
In work zones, you should drive at the posted speed limits. Reduce your speed even further when workers are on or near the road.
42 . A CMV should:
Have a fire extinguisher and other emergency equipment.
All commercial motor vehicles are required to be equipped with the proper emergency equipment. This may include spare electrical fuses; three red reflective triangles, six fuses, or three liquid burning flares; and at least one properly charged and rated fire extinguisher.
2026 District Of Columbia | Frequently Asked Questions
A CDL Class B license in the District of Columbia authorizes the holder to operate vehicles with a Gross Vehicle Weight Rating (GVWR) of 26,001 pounds or more, or any such vehicle towing another not in excess of 10,000 pounds. This includes buses, dump trucks, delivery trucks, and other medium to heavy commercial vehicles.
A Class B CDL license in the District of Columbia allows the holder to operate single vehicles with a Gross Vehicle Weight Rating of 26,001 pounds or more, or any such vehicle towing another not exceeding 10,000 pounds. This includes buses, dump trucks, segmented buses, delivery trucks, and utility trucks.
To acquire a Class B CDL license in District of Columbia, you must be at least 21 years old, possess a valid DC driver's license, pass a vision test, and complete a commercial driver's license application. You'll also need to pass a general knowledge test and a skills test, which includes a pre-trip vehicle inspection, a basic control skills test, and an on-road driving test.
In the District of Columbia, you must be at least 21 years old to qualify for a Class B CDL license. This is the age requirement set by the Federal Motor Carrier Safety Administration for interstate travel. However, some states may allow individuals aged 18 and above to drive within that state's borders.
While not always necessary, specific endorsements can expand the types of vehicles you can operate with a Class B CDL license in the District of Columbia. These include passenger vehicles (P), school buses (S), and tank vehicles (N). Each endorsement requires additional testing.
The Class B CDL skills assessment in the District of Columbia encompasses three main parts: a pre-trip vehicle inspection, a basic vehicle control test, and an on-road driving test. These tests assess your ability to inspect your vehicle, control its basic functions, and drive it safely on the road.
Yes, Class B CDL license holders in the District of Columbia are limited to operating vehicles with a Gross Vehicle Weight Rating (GVWR) of 26,001 pounds or more. They can also tow trailers that weigh less than 10,000 pounds. They cannot operate Class A vehicles without the appropriate endorsement.
Yes, in the District of Columbia, the written Class B CDL test is available in several languages other than English. However, federal regulations require all CDL holders to read and speak English sufficiently to converse with the general public, understand highway traffic signs and signals, respond to official inquiries, and make entries on reports and records.
Yes, in the District of Columbia, test accommodations for people with disabilities are available for the Class B CDL written exam. You can request accommodations through the DC Department of Motor Vehicles. However, you need to provide supporting documentation of your disability to qualify for these accommodations.
Yes, if you don't pass the Class B CDL written test in the District of Columbia, you can retake it. However, you must wait at least three business days before retesting. If you fail six times within a year, you'll have to wait one year from the date of the last test before retaking it.