Knowledge Test Class B #1
Class B Driving Test | District Of Columbia 2025 #1
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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1 . 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.
2 . Federal and state laws require:
Drivers to inspect their vehicles, but only if they will be transporting hazardous materials.
Commercial drivers are required by federal and state laws to inspect their vehicles before every trip. Regular inspections can help drivers identify issues before they become dangerous and costly.
3 . Before a vehicle with dual air brakes is driven, pressure of at least ____ should be built up in both braking systems.
100 psi
Before driving a vehicle with a dual air brake system, allow time for the air compressor to build up pressure of at least 100 psi in both the primary and secondary systems.
4 . In very hot weather, tires should be checked regularly because:
The lug nuts may loosen.
Air expands as it gets warmer, so the air pressure in your tires could reach dangerously high levels while being used in very hot weather. If this happens, stop and let your tires cool. Do not let air out of the tires, as this could result in the pressure dropping to an unsafe level once the tires cool down.
5 . During an applied leakage test, the maximum leakage rate for a double combination vehicle is:
4 psi in a minute.
It is important to know the maximum air loss rate that is safe for your specific vehicle. A double combination vehicle should have a leakage rate no higher than 4 psi in a minute during an applied leakage test.
6 . What is black ice?
Ice that is easily seen
Black ice is a thin layer of ice that is clear enough for the road surface to be seen through it. A road covered in black ice may look like it is merely wet.
7 . When stopping, the brake pedal:
Should be lifted up gradually.
When stopping, the brake pedal should be pushed down gradually. Control the pressure so your vehicle comes to a slow, safe stop.
2025 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.