OH · GK Endorsement

Ohio General Knowledge CDL Practice Test

Below are 25 exam-style questions for the Ohio General Knowledge CDL knowledge test, modeled on the FMCSA-aligned content used by the Ohio Bureau of Motor Vehicles. 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

Stopping distance is made up of:

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

Correct answer: C

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

Question 2 of 25

When you are being tailgated, you should:

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

Correct answer: D

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

Question 3 of 25

Black ice is most likely on:

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

Correct answer: D

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

Question 4 of 25

What does GVWR stand for?

A Government Vehicle Weight Regulation
B Gross Vehicle Width Rating
C General Vehicle Weight Reading
D Gross Vehicle Weight Rating

Correct answer: D

GVWR is the maximum weight the manufacturer says a single vehicle can safely weigh, including itself plus its load.

Question 5 of 25

To recover from a front-wheel skid, you should:

A Release the brake, let the wheels turn freely, and let the vehicle slow down
B Steer sharply in the opposite direction
C Accelerate
D Brake hard immediately

Correct answer: A

A front-wheel skid is usually caused by braking too hard. Release the brake to allow the front tires to grip again so steering returns.

Question 6 of 25

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

A Nothing — federal rules do not require marking
B Yellow tape only
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 7 of 25

Skids are most often caused by:

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

Correct answer: A

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 8 of 25

When the road is slippery, you should:

A All of the above
B Slow down
C Make smooth steering and braking inputs
D Increase following distance

Correct answer: A

Slippery roads require all three: more cushion, smoother inputs, and lower speed.

Question 9 of 25

A Class C CDL is required to drive:

A Vehicles designed to carry 16+ passengers including the driver, or that require hazmat placards
B Class A combinations only
C Any vehicle over 26,001 lbs
D Tractor-trailers under 26,001 lbs GCWR

Correct answer: A

Class C covers vehicles that don't meet Class A or B but are designed to carry 16 or more passengers (including the driver) or carry placarded amounts of hazardous materials.

Question 10 of 25

Which of the following is a sign of fatigue?

A Trouble remembering the last few miles
B Drifting in your lane
C All of the above
D Frequent yawning

Correct answer: C

All three are classic fatigue indicators in the FMCSA model. Cold air, music, and caffeine are not effective fixes — only sleep is.

Question 11 of 25

Acceleration must be smooth and gradual to avoid:

A Engine damage
B Wasting fuel only
C Powertrain wear and possible loss of control on slippery surfaces
D Annoying passengers

Correct answer: C

Quick throttle inputs on slick surfaces can spin the drive wheels and cause a tractor jackknife. Smooth acceleration avoids this and reduces wear.

Question 12 of 25

How does ABS help in an emergency stop?

A It prevents wheel lockup so the driver can keep steering
B It always stops the vehicle in a shorter distance
C It applies the parking brake
D It increases brake pressure automatically

Correct answer: A

ABS keeps the wheels rolling so steering control is preserved. It is not a shorter-distance device.

Question 13 of 25

Hydroplaning is most likely when:

A You brake hard on dry pavement
B Roads are dry but hot
C Tires lose contact with the road on a film of water
D Tires are over-inflated

Correct answer: C

Hydroplaning happens when tires ride on top of standing water at speed. Reduce risk by slowing down, keeping tires properly inflated and tread depth adequate.

Question 14 of 25

A driver may keep moving when:

A A passenger door is open
B Required emergency equipment is missing
C A trailer brake light is out
D A vehicle is in safe operating condition

Correct answer: D

Federal rules forbid driving any CMV that is not in safe operating condition. Continue only after the defect is fixed.

Question 15 of 25

You may not drive a CMV with a blood-alcohol concentration of:

A 0.10% or higher
B 0.04% or higher
C 0.08% or higher
D Any detectable amount above 0.00%

Correct answer: B

0.04% is the regulatory limit for CMV operation. A detectable amount under that triggers an out-of-service order but is not necessarily a DUI conviction.

Question 16 of 25

The most important hand position on the steering wheel is:

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

Correct answer: A

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 17 of 25

Which is true about driving in rain?

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

Correct answer: A

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 18 of 25

When approaching a railroad crossing in a CMV that is not required to stop, you should:

A Cross at maximum speed to get over quickly
B Slow down, look, listen, and be prepared to stop
C Always come to a full stop regardless of traffic
D Honk and proceed

Correct answer: B

Even when not required by class to stop, you must always be prepared to stop. Buses, hazmat, and certain other vehicles must stop every time.

Question 19 of 25

Which is true about communicating in heavy traffic?

A Make eye contact only when stopped
B Tap the horn lightly or flash lights to signal your presence
C Honk loudly to warn other drivers
D Never communicate; just drive

Correct answer: B

A light tap of the horn or a brief headlight flash communicates your presence without startling others. A loud, prolonged horn can provoke aggressive responses.

Question 20 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 21 of 25

When checking the engine compartment, you should make sure that:

A All of the above
B Power steering fluid is at the proper level
C Coolant level is above LOW and the cap is secure
D Engine oil level is safe to operate

Correct answer: A

A proper engine-compartment check covers oil, coolant, power steering fluid, windshield washer fluid, hoses, belts, and electrical wiring. Skipping any one of them defeats the purpose of the inspection.

Question 22 of 25

Hours-of-service records are required to be kept by:

A The carrier only
B The dispatcher only
C No one
D The driver, in the form of a logbook or electronic logging device

Correct answer: D

Drivers are responsible for accurate hours-of-service records, kept either on paper logs or, for most carriers, on an ELD.

Question 23 of 25

When approaching a curve, you should:

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

Correct answer: C

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

Question 24 of 25

Drivers may not drive after being on duty:

A 8 hours in any 24-hour period
B 15 hours of driving
C 20 hours in a 24-hour period
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 25 of 25

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

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

Correct answer: C

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

Study tips for the Ohio General Knowledge exam

The General Knowledge portion of the Ohio CDL exam is graded out of the bank of questions the Ohio Bureau of Motor Vehicles draws from each year. While the exact bank is not published, every question is sourced from the General Knowledge chapter of the Ohio 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 Ohio 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 Ohio Bureau of Motor Vehicles 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 Ohio 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 Ohio 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 Ohio Bureau of Motor Vehicles office.

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

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