KY · GK Endorsement

Kentucky General Knowledge CDL Practice Test

Below are 25 exam-style questions for the Kentucky General Knowledge CDL knowledge test, modeled on the FMCSA-aligned content used by the Kentucky Transportation Cabinet. Try to answer each question on your own before reading the answer key directly under it. The questions and answer choices are shuffled deterministically per state and endorsement, so the order will stay the same on repeat visits — that lets you genuinely measure your improvement.

Heads up: this is a study tool, not a graded exam. Cover the answer with your hand or a sheet of paper for an honest practice run, then re-read the explanations for any questions you missed. Aim for 22 out of 25 or better, three times in a row, before scheduling the real exam.

Question 1 of 25

Cargo that hangs more than 4 feet beyond the back of the vehicle must be marked with:

A Yellow tape only
B Nothing — federal rules do not require marking
C A green flag
D A red flag (or red light at night) at the extreme rear

Correct answer: D

Federal rules require a red flag during the day and red lights at night for projecting cargo beyond 4 feet.

Question 2 of 25

The most important hand position on the steering wheel is:

A One hand at 12
B 12 and 6
C Both hands at the bottom
D 10 and 2 (or 9 and 3)

Correct answer: D

A balanced grip at 10-and-2 or 9-and-3 gives the most control. One-handed and bottom-of-wheel positions reduce reaction time.

Question 3 of 25

A driver must report any accident involving a CMV to the carrier within:

A 24 hours
B 7 days
C 1 hour
D A reasonable time, before going off duty

Correct answer: D

FMCSA rules require notification of the motor carrier in a reasonable time — most policies treat that as before going off duty.

Question 4 of 25

You are driving a heavy vehicle and have to stop on a long downgrade. Which is the safest way?

A Use the parking brake to slow down
B Pump the brakes hard and fast
C Disengage the clutch and coast
D Use a low gear and steady moderate brake application

Correct answer: D

On a long downgrade, select a low gear before the descent and use steady, light to moderate braking. Hard pumping or coasting in neutral leads to brake fade and loss of control.

Question 5 of 25

Skids are most often caused by:

A Old tires
B Driving too fast for conditions
C Manual transmissions
D Properly working brakes

Correct answer: B

The dominant cause of skids identified by the FMCSA is driving too fast for the road or weather. Sudden steering, hard braking, or hard acceleration usually triggers them.

Question 6 of 25

Which is true about driving in rain?

A High beams improve visibility in heavy rain
B Tire chains are required by federal law
C It is safe to drive at the posted speed limit
D Roads are most slippery just after rain begins, when water mixes with road oil

Correct answer: D

The first few minutes of rain mix with oil and grime on the road and create the slipperiest conditions. Slow down and increase following distance.

Question 7 of 25

A driver who refuses to take a required drug or alcohol test is treated as if they:

A Took the test and passed
B Need to take it again later
C Did not take the test, with no consequence
D Took the test and failed

Correct answer: D

Refusal is a federal CDL disqualification with the same consequences as a positive test.

Question 8 of 25

Black ice is most likely on:

A Concrete pavement only
B Roads in direct sunlight
C Bridges and overpasses
D Gravel surfaces

Correct answer: C

Bridges and overpasses freeze first because cold air circulates above and below them. They are the most-asked test scenario for sudden ice.

Question 9 of 25

Which is true about driving in fog?

A Use high-beam headlights for maximum visibility
B Use low-beam headlights and slow down
C Drive faster to get out of the fog quickly
D Use the four-ways while in motion at highway speed

Correct answer: B

High beams reflect off fog and reduce visibility. Slow down and use low beams or fog lamps if equipped.

Question 10 of 25

When you are being tailgated, you should:

A Move to the left lane only
B Brake suddenly to teach a lesson
C Increase your following distance from the vehicle in front to give both of you more room
D Speed up to get away

Correct answer: C

Adding cushion ahead gives the tailgater room to pass safely and reduces the chance of a chain rear-end collision.

Question 11 of 25

When should you use four-way flashers?

A Whenever you feel like it
B Only at night
C When you are stopped or moving slowly enough to be a hazard
D Only on the highway

Correct answer: C

Four-ways are for vehicles stopped on or near the road or moving so slowly that they are a hazard.

Question 12 of 25

When approaching a curve, you should:

A Brake while in the curve
B Downshift in the curve
C Stay at the same speed
D Slow down before entering and accelerate gently through it

Correct answer: D

Speed should already be set before the curve. Braking or downshifting in a curve can upset the vehicle's balance.

Question 13 of 25

Drivers may not drive after being on duty:

A 20 hours in a 24-hour period
B 8 hours in any 24-hour period
C 15 hours of driving
D 14 consecutive hours since coming on duty

Correct answer: D

The 14-hour rule limits the on-duty window during which up to 11 hours of driving may occur.

Question 14 of 25

Which of the following is a valid reason to refuse a load?

A All of the above
B It would make you exceed federal hours-of-service rules
C It would push your weight over legal limits
D The cargo is not properly secured or placarded

Correct answer: A

A driver is required by federal law to refuse loads that violate HOS, weight, or hazmat rules. The driver, not the dispatcher, is liable.

Question 15 of 25

Which of the following is the correct order for the seven-step pre-trip air-brake check (last steps shown)?

A Test the low-air warning then drive
B Test only the air-leak rate
C Test the parking brake then the service brake
D Test the service brake then the parking brake

Correct answer: C

In the standard FMCSA seven-step procedure, the parking brake is tested before pulling away, then the service brake stop is the final step.

Question 16 of 25

A leaking exhaust system is dangerous because:

A It increases fuel use
B It causes the engine to overheat
C It is illegal
D It can let poisonous carbon monoxide into the cab

Correct answer: D

Carbon monoxide from a leaking exhaust can cause headaches, drowsiness, and unconsciousness. The illegality is real but the safety risk is the bigger answer.

Question 17 of 25

When approaching a steep downgrade, the basic safe-driving rule is:

A Stay in high gear
B Use the parking brake intermittently
C Coast in neutral
D Select a lower gear before starting down

Correct answer: D

Get into a low gear before the descent so the engine helps hold the vehicle back.

Question 18 of 25

Which of the following is NOT part of a pre-trip inspection?

A Adjusting the trailer brakes individually
B Walking around the vehicle and checking lights
C Testing the service and parking brakes
D Checking the engine compartment

Correct answer: A

Adjusting brakes is a maintenance task done by qualified personnel, not a pre-trip step. The driver checks for proper operation, not adjustment.

Question 19 of 25

Which is true about driving in mountains?

A All of the above
B Brakes alone are not designed to hold a heavy vehicle on a long downgrade
C Engine braking helps keep speed under control
D Heavy vehicles can slow down sharply on grades

Correct answer: A

Mountain driving combines all three. Use of low gears, engine braking, and short, moderate service-brake applications is the safe combination.

Question 20 of 25

Which is true about brake lining wear and adjustment?

A Slack adjusters need periodic checking; pushrod travel beyond limits is out-of-service
B Drum brakes never need adjustment
C Brake adjustment is the dispatcher's responsibility
D Brakes self-adjust forever

Correct answer: A

Slack adjusters can fail, and pushrod travel must be within limits. Drivers check; adjustment itself is a maintenance task for qualified personnel.

Question 21 of 25

Stopping distance is made up of:

A Brake-lag distance only
B Perception distance + reaction distance + brake-lag distance + braking distance
C Speed times weight
D Reaction distance only

Correct answer: B

Total stopping distance has four parts. Air brakes add a brake-lag distance not present in hydraulic systems.

Question 22 of 25

Which is true about the use of turn signals?

A Signal early, signal continuously, and cancel after the turn
B Signal only at the moment you start turning
C Use the four-way flashers instead of signals at intersections
D Signal only when other vehicles are present

Correct answer: A

The federal model manual specifies signal early, continuously, and cancel after — the same three steps every state CDL test asks about.

Question 23 of 25

The two main reasons why a driver's feet are kept off the brakes when not actively braking are:

A To rest the right leg
B To save fuel and improve mileage
C To save brake pads and reduce drag
D So the brake lights don't mislead following drivers and so the brakes don't overheat

Correct answer: D

Riding the brake lights confuses drivers behind you and gradually heats the friction surfaces, both of which are safety problems.

Question 24 of 25

The minimum tread depth for steer-axle tires is:

A 1/32 inch
B 6/32 inch
C 2/32 inch
D 4/32 inch

Correct answer: D

Steer tires must have at least 4/32 inch in every major groove. Other tires require at least 2/32 inch.

Question 25 of 25

Stab braking is used:

A On vehicles with ABS
B To save fuel
C On vehicles without ABS, to keep them straight in an emergency
D On wet roads only

Correct answer: C

Stab braking — full application then release as soon as wheels lock, then re-apply — is for non-ABS vehicles. With ABS, do not pump.

Study tips for the Kentucky General Knowledge exam

The General Knowledge portion of the Kentucky CDL exam is graded out of the bank of questions the Kentucky Transportation Cabinet draws from each year. While the exact bank is not published, every question is sourced from the General Knowledge chapter of the Kentucky CDL handbook, which itself is derived from the FMCSA Model Commercial Driver's License Manual. That means studying our practice tests, reading the corresponding handbook chapter, and re-reading the parts you got wrong is genuinely the most efficient route to a first-time pass.

Most successful applicants follow a simple cycle: take the practice test cold, write down every question you missed, open the matching chapter of the official Kentucky handbook, re-read the section that contains the right answer, then re-take the practice test 24 to 48 hours later. The 24-hour delay matters — sleep is when your brain commits new information to long-term memory, and CDL knowledge questions reward that kind of consolidated learning rather than cramming.

Pay particular attention to questions that include qualifier words like always, never, only, primary, or most. CDL test writers love to flip the right answer with a single qualifier. When two answer choices look almost identical, pay attention to the verb (is it must, should, or may?) and to any numbers (14 days, 100 air miles, 8 hours, 70/8 split). On endorsement tests in particular, watch for trick framing where a true statement about a different endorsement is offered as the "correct" answer to a question that is actually about General Knowledge.

Test-day logistics matter too. Bring photo ID, your Social Security card or birth certificate, your medical examiner's certificate (DOT card), and proof of state residency if you haven't already submitted those documents. The Kentucky Transportation Cabinet will not let you sit for the knowledge exam without your documentation, and most offices charge an additional fee for re-attempts. Arrive early — the wait at most CDL testing offices runs 30 to 60 minutes — and silence your phone before the exam begins.

Finally, keep your General Knowledge fundamentals sharp even when you're focused on the General Knowledge exam. Many states administer multiple knowledge tests in a single sitting, and questions on weight definitions (GVWR, GCWR, GAWR), stopping distance, and the pre-trip inspection routine show up across endorsements. If you're unsure on the basics, sit a fresh Kentucky General Knowledge practice test before scheduling the real exam.

Next steps

Missed more than four questions? Re-read the General Knowledge study guide and the matching chapter in the official Kentucky CDL handbook. Then come back and re-take the test. Once you can score 22 of 25 or higher on three runs in a row, you're in good shape to schedule the real exam at your local Kentucky Transportation Cabinet office.

Already comfortable with this endorsement? Drill another: KY Air Brakes · KY Combination Vehicles · KY Hazardous Materials · KY Passenger · KY School Bus · KY Tank Vehicle · KY Doubles / Triples

New to the CDL process in Kentucky? Read How to apply for a CDL in Kentucky for the document checklist and step-by-step timeline.