Knowledge Test Class B #2
Class B Driving Test | District Of Columbia 2025 #2 Page 5 of 7
Train for FREE online with our District Of Columbia class B 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 B permit in 2025, 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 B requirements may vary from state to state.
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29 . A low air pressure warning signal should activate:
When tank pressure falls below 5 psi.
In an air brake system, a low air pressure warning signal must come on if air pressure in the tanks falls below 60 psi. This warning signal may come in the form of a light, a buzzer, or a wig wag.
30 . Most CDL holders have ____ licenses.
Non-exempted
Most CDL holders who drive CMVs in interstate commerce are non-excepted interstate commerce drivers.
31 . In a vehicle with dual air brakes, what happens if one system is low on pressure?
The low system will use an auxiliary system to fill the tank.
In a dual air brake system, if one of the air systems gets very low on pressure, either the front or rear brakes will not be operating fully. You should bring your vehicle to a safe stop and have the air system repaired.
32 . Some air brake systems use alcohol:
To reduce the risk of rust forming on air brake valves.
Some air brake systems contain an alcohol evaporator. This device introduces alcohol into the braking system to inhibit the formation of ice.
33 . While driving, spring brakes are generally held in place by:
Sturdy ties.
While driving, spring brakes are generally held in place by air pressure. If the air pressure gets low enough, the springs will activate the brakes.
34 . When approaching a curve during the on-road driving test, you must do all of the following, except:
Steadily use the brakes throughout the curve.
When approaching a curve during the on-road driving test, you should thoroughly check traffic in all directions. Before entering the curve, reduce your speed sufficiently so that further braking or shifting is not required. Keep your vehicle in its lane and continue checking traffic in all directions.
35 . Hydroplaning occurs when:
Front tires have less traction than rear tires.
Hydroplaning is an effect that occurs on wet roads when tires lose traction with the road surface and begin gliding along on a layer of water.
2025 District Of Columbia | Frequently Asked Questions
In the District of Columbia, a CDL Class A license allows the holder to operate any combination of vehicles with a Gross Combination Weight Rating (GCWR) of 26,001 pounds or more, provided the Gross Vehicle Weight Rating (GVWR) of the vehicle(s) being towed is over 10,000 pounds. This includes tractor-trailers, truck and trailer combinations, and flatbeds.
A Class A CDL license in the District of Columbia permits the holder to operate various types of larger, heavier commercial vehicles. This includes tractor-trailers, truck and trailer combinations, tank vehicles, livestock carriers, and flatbeds. The vehicles can have a Gross Combination Weight Rating (GCWR) of 26,001 pounds or more if the towed vehicle is over 10,000 pounds.
To obtain a Class A CDL license in the District of Columbia, you must be at least 21 years old, possess a valid non-commercial driver's license, pass a vision test, and provide proof of residency and identity. You'll also need to pass written knowledge tests, obtain a Commercial Learner's Permit (CLP), and successfully complete a skills and road test.
In the District of Columbia, you must be at least 21 years old to qualify for a Class A Commercial Driver's License (CDL). This age requirement is consistent across all states and is set by federal regulation. This allows for interstate operation of commercial vehicles. For intrastate (within the same state), the minimum age can be 18.
Specific endorsements are not required for a Class A CDL license but they can provide additional driving privileges. These include endorsements for operating vehicles like school buses, passenger vehicles, tank vehicles, and vehicles carrying hazardous materials. Each endorsement requires passing specific knowledge and skills tests.
The Class A CDL skills test in the District of Columbia consists of three parts: the vehicle inspection test, the basic control skills test, and the road test. The vehicle inspection test involves checking the vehicle's safety components, the basic control skills test assesses your ability to maneuver and control the vehicle, and the road test evaluates your on-road driving skills.
Yes, limitations can be imposed on Class A CDL license holders in the form of restrictions. These are based on the driver's abilities or the type of vehicle they tested in. For example, if a driver takes the skills test in an automatic transmission truck, they will have an 'E' restriction, limiting them to automatic transmission vehicles only.
Yes, it is possible to take the written Class A CDL test in languages other than English in the District of Columbia. However, the Federal Motor Carrier Safety Administration requires 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, you can request accommodations for the Class A CDL written test in the District of Columbia due to disability. The DMV is committed to providing accessible services and accommodations to individuals with disabilities. You should contact the DMV directly in advance of your test to discuss your needs and the potential accommodations available.
If you don't pass the Class A CDL written test in the District of Columbia, you are allowed to retake it. However, you must wait three days before retaking the test. If you fail the test three times, you must wait 90 days before taking it again. There's also a retesting fee that applies each time.