10 exam-style questions with answers and explanations, straight from our 1,030-question bank. Tap an answer to check yourself. When you're ready, take the scored version in the free practice test.
These 10 free SC-CDL questions are organized by exam domain, so you can see how each part of the South Carolina CDL Permit Test blueprint is tested. Reveal the answer and explanation under each question.
A 60-foot tractor-semitrailer is traveling at 55 mph on a dry highway. Traffic is steady, and no extra margin is needed for weather or visibility. How much following time is required by the standard CDL rule?
Correct answer: B - 7 seconds
At 45 mph, the right wheels of a loaded straight truck drop onto a firm shoulder about three inches below the pavement. The truck remains stable, and there is no obstacle ahead. Which technique should the driver use to return to the roadway?
Correct answer: D - Hold the wheel straight, ease off, slow to about 20 mph or less, then reenter gradually and countersteer
A flatbed driver inspects the cargo before departure and again at mile 45. After driving another 70 miles, the driver stops for a scheduled meal break. No movement of the load is visible. At what point must the securement be checked again?
Correct answer: A - Before resuming the trip after the break
On low beams, a driver can see about 250 feet ahead. At 55 mph, the air-braked truck may need more than 450 feet to stop. The road is dry and otherwise clear. Which conclusion should govern the driver's speed?
Correct answer: C - Speed must be reduced until the truck can stop within the illuminated distance
Before a long downgrade, a driver selects the proper low gear and chooses 35 mph as the safe speed. The truck reaches 35 mph during the descent. How should the driver perform the next braking cycle?
Correct answer: A - Apply the brakes firmly to about 30 mph, release them, and let speed rise to 35 mph before repeating
During a pre-trip inspection, a driver measures 3/32 inch of tread in every major groove of the left steering tire, 5/32 inch on the right steering tire, and 2/32 inch on each rear tire. No tire has visible damage. Which finding prevents dispatch?
Correct answer: B - The left steering tire is below the required tread depth
At highway speed, a tractor-trailer driver hears a loud bang, feels strong vibration, and notices the vehicle pulling to one side. What is the correct initial response to the suspected blowout?
Correct answer: D - Grip the wheel firmly, avoid braking at first, stabilize the truck, then slow gradually and pull off
A driver tests a combination vehicle at full air pressure with the engine off, wheels chocked, and parking brakes released. With the service brake fully applied and pressure stabilized, the system loses 3 psi in one minute. What does this measurement indicate?
Correct answer: C - The applied leakage is within the 4 psi-per-minute limit, so the inspection may continue
During an in-cab air-brake test, governor cutout occurs at 125 psi. The low-air warning first activates at 48 psi, and the spring-brake control pops out at 28 psi. What does this pair of readings show?
Correct answer: C - The warning activates too late, while the 28-psi pop-out is within the typical range
The blue service line to a semitrailer becomes disconnected, but the red emergency/supply line remains connected and charged. Which trailer-brake condition is most likely before any additional failure occurs?
Correct answer: A - Trailer service braking may be lost while the trailer emergency brakes remain released
The SC-CDL exam also covers these domains. Drill them in the full free practice test:
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