South Carolina CDL General Knowledge Practice Test 2025

The SCDMV CDL General Knowledge test has 50 questions requiring 40 correct (80%) to pass. Endorsement tests: HazMat (30 questions), Tanker (30 questions), Passenger (20 questions), School Bus (20 questions), Doubles/Triples (20 questions), Air Brakes (25 questions). All endorsements require 80%. HazMat also requires TSA security clearance.

South Carolina CDL holders in a CMV face the federal 0.04% BAC limit. South Carolina's standard DUI threshold is 0.08%. A DUI conviction in any vehicle triggers FMCSA CDL disqualification: 1 year for first offense, lifetime for second. Emma's Law's IID requirement applies to personal vehicles — but the underlying DUI conviction creates long-term CDL employment barriers regardless of the IID itself.

SCDMV CDL knowledge tests are available at SCDMV branch offices and approved Third Party Testing sites statewide. CDL skills tests are administered at SCDMV-approved TPT locations. South Carolina has CDL testing in Columbia, Charleston, Greenville, Spartanburg, Florence, and other cities. Contact SCDMV for current testing schedules and fee information.

South Carolina's Alcohol and Drug Safety Action Program (ADSAP) is required for all DUI convictions as a condition of license reinstatement. ADSAP is an assessment and education/treatment program administered through county ADSAP programs. CDL holders convicted of DUI must complete ADSAP in addition to the FMCSA CDL disqualification period. ADSAP completion is a condition of both standard driver's license AND CDL reinstatement in South Carolina.

South Carolina CDL drivers must carry: (1) a valid CDL; (2) current medical certificate (DOT physical) on file with SCDMV if operating a vehicle requiring CDL medical certification; (3) registration and proof of insurance for the vehicle; (4) HazMat shipping papers and placards if carrying hazardous materials; (5) DVIR from the previous driver; (6) for interstate operations, Hours of Service records (logs or ELD data). South Carolina Transport Police conduct roadside inspections and may request all of these documents.

A Class A CDL allows you to operate any combination of vehicles with a Gross Vehicle Weight Rating (GVWR) of 26,001 lbs or more, provided the towed unit exceeds 10,000 lbs — this includes tractor-trailers and double/triple trailer rigs. A Class B CDL covers single vehicles with a GVWR of 26,001 lbs or more, or any such vehicle towing a unit not exceeding 10,000 lbs — this includes straight trucks and large buses. A Class C CDL is required for vehicles designed to carry 16 or more passengers (including the driver) or for vehicles transporting hazardous materials that require placarding, when those vehicles do not qualify for Class A or B.

CDL fees vary by state and by the class and endorsements you obtain. Most states charge separate fees for the CDL knowledge test ($10–$30 per attempt), the CDL skills test ($50–$150), and the CDL license itself ($50–$100). Additional fees apply for each endorsement (HazMat, Tanker, Passenger, etc.). The HazMat endorsement also requires a TSA security threat assessment fee of approximately $86. Check your South Carolina DMV website for current fee schedules.

Federal regulations (49 CFR 383.133) require that CDL applicants be able to read and speak the English language sufficiently to understand highway traffic signs and signals and to respond to official inquiries. Many states offer CDL knowledge tests in Spanish and other languages for non-commercial knowledge questions, but the actual CDL test must be taken in a language that allows the driver to meet the English proficiency requirement. Check with the South Carolina DMV for available language options.

In most states, a CDL is valid for 4–8 years (commonly 4–5 years). To renew your South Carolina CDL, you typically need to visit a DMV office, pass a vision test, pay the renewal fee, and update your medical certification (DOT physical). If you hold a HazMat endorsement, your TSA background check must also be current. CDLs cannot generally be renewed online due to federal requirements for in-person verification of medical certification.

If you fail the CDL General Knowledge test in South Carolina, you are typically required to wait a specified period (commonly 1–7 days) before retaking it. Most states allow 2–3 attempts before requiring additional waiting periods or study requirements. There is usually a retest fee for each attempt. Focus on the areas you missed — most states provide a score sheet showing which topic areas you need to review.