Kentucky CDL practice tests
Kentucky hands CDL testing to a law enforcement agency rather than its motor vehicle office. Kentucky State Police runs both the knowledge and skills tests, and the skills test fee itself depends on how long the applicant has already held a Kentucky operator license, $50 for 30 days or more and $150 for less.
The written exams themselves are federal. Kentucky decides the permit rules, the fees and who runs the skills test, but the knowledge you are tested on comes from 49 CFR Part 383 and is the same in every state, which is why the 145 questions here work wherever you apply.
What changes in this state
Commercial learner permit
Kentucky requires an applicant to hold the commercial learner permit for at least 14 days before taking the skills test, and the standard permit is valid for 180 days from issuance.
Kentucky Transportation Cabinet, Commercial Driver's License, checked 2026-08-28
Fees
A commercial learner permit costs $11, or $14 for the REAL ID version, and full CDL fees range from $18.75 to $50 depending on class and endorsements.
Kentucky Transportation Cabinet, Commercial Driver's License, checked 2026-08-28
Where you test
Both the knowledge test and the skills test in Kentucky are scheduled and administered by Kentucky State Police rather than by driver licensing offices, with knowledge tests booked online and skills tests booked by phone.
Kentucky State Police, Driver Testing, checked 2026-08-28
Every knowledge area
General Knowledge
Required of every applicant: inspection, control, space and speed management, hazard perception, emergencies and hours of service.
Air Brakes
Fail this and an L restriction bars you from any vehicle with air brakes, which is most of them.
Combination Vehicles
Coupling, the fifth wheel, off tracking and trailer swing. Needed for Class A.
Hazardous Materials
Placards, shipping papers, segregation and the security threat assessment.
Tank Vehicles
Liquid surge, baffles, outage and why a tanker rolls over so readily.
Doubles and Triples
Rearward amplification, converter dollies and coupling a second or third trailer.
Passenger Transport
Bus inspection, standee lines, passenger supervision and railroad crossings.
School Bus
Danger zones, loading and unloading, student crossing and evacuation.