Knowledge Test Class B #1
Class B Driving Test | South Carolina 2026 #1 Page 7 of 7
Train for FREE online with our South Carolina 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 SC CDL class B 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 B requirements may vary from state to state.
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43 . What does the air compressor governor do?
Controls the temperature of the air leaving the air storage tanks.
In an air brake system, the air compressor governor controls when the air compressor pumps air into the air storage tanks.
44 . If being tailgated, you should speed up.
If someone is tailgating you, it is a good idea to open up the space ahead of your vehicle to make it easier for the driver to pass you. Increasing your speed is not a good idea because the driver may continue to tailgate you at the higher speed, only increasing the danger.
45 . Noting the speed of other vehicles is one way to determine when to upshift.
There are two indicators that determine when you need to shift into a higher gear. One indicator is the engine speed (rpm). You should read your vehicle's manual to learn its rpm range and shift up when you reach the top of that range. The other indicator is road speed (mph). You should learn which speeds each gear can accommodate, then keep an eye on the speedometer and shift up as needed.
46 . To help your vehicle be seen by others:
Your headlights should be used, but only in the rain.
A vehicle's headlights should be clean during trips. This will ensure that the lights can provide as much light as possible, helping the vehicle to be seen.
47 . When carrying a wide load, a driver should:
Drive on the shoulder.
Loads that are over-length, over-width, or overweight require special permits and may be subject to restrictions, such as being allowed on the road only at certain times of the day.
48 . An applicant may label parts of the vehicle that will be covered in the pre-trip inspection.
When taking the pre-trip inspection test, you may not have labels placed on parts of the vehicle to help you remember which parts need to be inspected or their weight in scoring. Labels placed by the manufacturer are acceptable as long as they are not excessive.
49 . Which of the following is not a type of retarder?
Electric
Retarders are mechanisms in some vehicles that help slow a vehicle and reduce the need for braking. The four basic types of retarders are exhaust, engine, hydraulic, and electric.
50 . Anti-Lock Braking Systems (ABS):
If equipped, ABS is in addition to a vehicle's normal braking system and does not increase or decrease the braking power of any other system. ABS only activates when a vehicle's wheels are about to lock.
See the exact questions that will be on the 2026 South Carolina DMV exam.
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2026 South Carolina | Frequently Asked Questions
To secure a CDL Doubles/Triples endorsement in South Carolina, you must first have a Commercial Driver's License (CDL). After that, you need to pass a written knowledge test on handling large vehicles. This test covers topics like coupling and uncoupling, inspecting doubles and triples, and anticipating and handling different driving situations.
To obtain a CDL Doubles/Triples license, you must have a valid Commercial Driver’s License (CDL). Then, you'll need to pass a Doubles/Triples endorsement knowledge test. The test covers topics such as coupling and uncoupling, inspecting doubles and triples, and handling various driving situations. Training or experience driving these types of vehicles is also beneficial.
While it's not required by law, having practical training or experience driving double/triple trailers is highly beneficial and might be required by employers. The CDL Doubles/Triples endorsement primarily requires passing a knowledge test. However, understanding how to handle these large vehicles, including coupling/uncoupling and inspection procedures, is crucial for safety.
Yes, to obtain a CDL Doubles/Triples endorsement in South Carolina, you must pass a written knowledge test. This test covers specific topics related to driving doubles and triples, such as coupling and uncoupling, inspecting these types of vehicles, and handling various driving situations. It's an additional requirement beyond the general CDL license.
The CDL Doubles/Triples endorsement test is primarily a written exam, focusing on knowledge rather than practical skills or maneuvers. It covers areas like coupling and uncoupling, vehicle inspection, and handling specific driving situations. However, practical skills such as maneuvering these vehicles safely can be beneficial, even if not directly tested. Always check with your local DMV for specific requirements.
No, it is not permissible to operate double/triple trailers without a valid CDL Doubles/Triples endorsement in South Carolina. This endorsement is required by law to ensure that drivers have the necessary skills and knowledge to safely operate multiple trailers. Violating this requirement can result in penalties and potential loss of driving privileges.
You can append the CDL Doubles/Triples endorsement to your existing CDL license. You do not need to initiate a new application for a separate license. However, you will need to pass the Doubles/Triples knowledge test, and pay the appropriate fees to add this endorsement to your current CDL license. Always check with your local DMV for specific procedures.
Yes, drivers with a CDL Doubles/Triples endorsement are subject to specific rules and regulations. For instance, they must comply with weight restrictions, follow safety protocols for coupling and uncoupling trailers, and adhere to specific driving techniques. Additionally, they must abide by all general CDL rules, including maintaining a logbook and observing Hours of Service regulations.
In South Carolina, a combination vehicle (like a double or triple trailer) can have a maximum weight of 80,000 lbs. The maximum length for a double trailer is 61 feet for the two trailers combined. For triple trailers, the total combined length is typically limited to 75 feet. However, these restrictions can vary based on local regulations and the specific roadways being used.
Yes, there are specific safety guidelines and regulations in South Carolina for driving double/triple trailers with a CDL Doubles/Triples endorsement. These include maintaining proper following distances, adjusting driving techniques to account for the longer length and increased weight of the combination, and being aware of potential stability issues. It is important to adhere to these guidelines to ensure safe operation of double/triple trailers on the road.
