Free Ohio DMV CDL — General Knowledge Practice Test 2026
The Ohio CDL — General Knowledge knowledge test has ~50 questions, and you need ~40 correct (80%) to pass. Practice free with questions written from the official Ohio driver handbook — every one has a clear explanation, and you can retake as often as you like with no sign-up.
Content reviewed against official driver handbooks · August 12, 2026
What's on the Ohio written test
The Ohio CDL — General Knowledge knowledge test has ~50 questions; you need ~40 correct (80%) to pass.
Based on the official Ohio exam format — always confirm current details with your state DMV.
Practice by topic
Focus on one area at a time — each topic has its own set of Ohio practice questions.
Learn the shapes, colors, and meanings of regulatory, warning, and guide signs — from stop and yield to construction and school-zone signs.
Speed limits, turning and signaling rules, headlight and seat-belt requirements, and the everyday laws every driver must follow.
How to read traffic signals, lane lines, and pavement markings — including yellow and white lines, arrows, and flashing lights.
Who goes first at intersections, four-way stops, roundabouts, and crosswalks, and how to yield to pedestrians and emergency vehicles.
Following distance, scanning, blind spots, using your lights, and the habits that prevent crashes and keep you in control.
Driving safely around motorcycles, bicycles, large trucks, pedestrians, and school buses — and knowing who has the right of way.
Blood alcohol limits, zero-tolerance and implied-consent laws, and how alcohol and drugs — legal or not — affect your driving.
Legal and illegal parking, colored curbs, distances from hydrants and crossings, and how to park safely on hills.
Choosing a safe speed, keeping a space cushion, adjusting for weather and traffic, and understanding stopping distance.
What to do when things go wrong — brake failure, tire blowouts, skids, and stalling on railroad tracks.
The point system, license suspension, provisional-license rules, insurance requirements, and other licensing basics.
How to pass the first time
- Read the official Ohio driver handbook at least once before test day.
- Practice by topic to find your weak spots, then fix them.
- Take full-length practice tests until you pass comfortably every time.
- Read every explanation — understanding beats memorizing.
Ohio CDL — General Knowledge test — frequently asked questions
How many questions are on the Ohio CDL — General Knowledge test?
The Ohio CDL — General Knowledge knowledge test has ~50 questions, and you need ~40 correct (80%) to pass. Our practice tests mirror that format.
How many questions can I miss on the Ohio CDL — General Knowledge test?
You can miss up to ~10 of the ~50 questions and still pass — you need ~40 correct, which is 80%.
Can I retake the practice test?
Yes — practice as often as you like, completely free. The questions and answer choices are shuffled each time.
Can I take the Ohio practice test in Spanish?
Yes. Every question here is available in English and Spanish — switch languages anytime. Many states also offer the real knowledge test in languages other than English; confirm what Ohio offers with your DMV.
Can I practice on my phone?
Yes. The practice tests work in any mobile or desktop browser — no app or sign-up needed — so you can study anywhere.
Are these the real DMV test questions?
No. Our questions are original, written from the current official Ohio driver handbook to match the real test's topics and style. We are not affiliated with any DMV or government agency.
What's the best way to study?
Read the Ohio driver handbook, practice by topic to target weak areas, and finish with full-length tests until you consistently pass.
Other Ohio practice tests
Take the CDL — General Knowledge test in another state
Every Ohio question is written from the official Ohio driver handbook and checked against its current edition. DMV Test Free is a free, independent study resource — not affiliated with any DMV or government agency. About DMV Test Free
Ohio CDL — General Knowledge questions with answers
20 sample questions from the Ohio CDL — General Knowledge question bank — each with the correct answer, a short explanation, and the section of the official handbook it comes from.
Show all 20 questions with answers
1. How many placards must a placarded hazardous materials vehicle display, and where?
Correct answer: Four identical placards on the front, rear, and both sides
A placarded vehicle must show at least four identical placards, on the front, the rear, and both sides, readable from all four directions.
Source: Ohio CDL Driver Manual, Section 2 (Lists of Regulated Products)
2. If you fail the vehicle inspection portion of the skills test, what happens next?
Correct answer: You cannot continue to the basic control or road test
Failing the vehicle inspection test means you cannot continue to the basic control or road test that day; you must pass it before moving on.
Source: Ohio CDL Driver Manual, Section 1 (Skills Tests)
3. How do you stop a front-wheel skid?
Correct answer: Let the vehicle slow by easing off hard braking and steering
In a front-wheel skid the front tends to go straight no matter how you steer. The only cure is to let the vehicle slow down by easing off hard steering and braking.
Source: Ohio CDL Driver Manual, Section 2 (Front-wheel Skids)
4. While proceeding through an intersection, what should you not do?
Correct answer: Change lanes as you cross
Do not change lanes while going through an intersection. Keep your hands on the wheel, check traffic in all directions, and yield to pedestrians and traffic in the intersection.
Source: Ohio CDL Driver Manual, Section 13 (Intersections)
5. How is aggressive driving described, as opposed to road rage?
Correct answer: Operating selfishly and pushily without regard for others' safety
Aggressive driving is operating a vehicle in a selfish, bold, or pushy way without regard for others' rights or safety. Road rage goes further, with the intent to harm another driver.
Source: Ohio CDL Driver Manual, Section 2 (Aggressive Drivers / Road Rage)
6. Before changing lanes, in addition to signaling, what should you check?
Correct answer: Your mirrors, to be sure no one is beside you or in a blind spot
Put your turn signal on and check your mirrors before, during, and after the lane change to be sure no one is alongside or has moved into your blind spot.
Source: Ohio CDL Driver Manual, Section 2 (Lane Changes)
7. In the air leakage rate test on a single vehicle, how much may the air pressure drop in one minute?
Correct answer: No more than 3 psi
After the initial drop stabilizes, a single vehicle or trailer without air brakes should lose no more than 3 psi in one minute with the foot brake fully applied.
Source: Ohio CDL Driver Manual, Section 11 (Air Leakage Rate Test)
8. If a driver has any measurable alcohol below 0.04 percent, what happens?
Correct answer: The driver is placed out of service for 24 hours
Any detectable amount of alcohol under 0.04 percent puts the driver out of service for 24 hours rather than triggering a full disqualification.
Source: Ohio CDL Driver Manual, Section 1 (Disqualifications)
9. If you double your speed, roughly how much longer does your braking distance become?
Correct answer: About four times as long
Doubling your speed, such as from 20 to 40 mph, makes the braking distance about four times longer and the impact force about four times greater.
Source: Ohio CDL Driver Manual, Section 2 (Effect of Speed on Stopping Distance)
10. If you must swing into the oncoming lane to finish a turn in a large vehicle, how should you treat approaching traffic?
Correct answer: Leave them room to pass or stop, and do not back up
Watch for vehicles heading toward you and leave them room to pass or to stop. Do not reverse for them, because you could strike something or someone behind you.
Source: Ohio CDL Driver Manual, Section 2 (Right Turns)
11. On a steep mountain downgrade, what do the posted signs tell drivers about escape ramps?
Correct answer: Where along the grade the ramps are located
Signs along steep grades point out where the escape ramps are. Such ramps use soft material, sometimes combined with an upgrade, to bring a runaway vehicle to a safe stop.
Source: Ohio CDL Driver Manual, Section 2 (Brake Failure on Downgrades)
12. Which of the following is listed as a serious traffic violation for a CDL holder?
Correct answer: Speeding 15 mph or more over the posted limit
Excessive speeding of 15 mph or more over the limit is a serious violation, along with reckless driving, erratic lane changes, and following too closely.
Source: Ohio CDL Driver Manual, Section 1 (Serious Traffic Violations)
13. What is the rule about how many driver licenses a commercial driver may hold?
Correct answer: One license only
A commercial driver may hold only one license. Violating this rule can bring a fine of up to $5,000 or jail time.
Source: Ohio CDL Driver Manual, Section 1 (Other CDL Rules)
14. When should you move a severely injured person at an accident scene?
Correct answer: Only if fire or traffic makes leaving them in place dangerous
Do not move a badly injured person unless a danger such as fire or passing traffic makes it necessary. Otherwise you risk making injuries worse.
Source: Ohio CDL Driver Manual, Section 2 (Care for the Injured)
15. Which headlights should you use when driving in fog?
Correct answer: Low-beam headlights and fog lights
Use low-beam headlights, and fog lights if you have them, for the best visibility in fog even during the day. High beams reflect off the fog and reduce what you can see.
Source: Ohio CDL Driver Manual, Section 2 (Driving in Fog)
16. Why are drivers who are in a hurry a particular hazard to a commercial vehicle?
Correct answer: They may pass unsafely or cut in front, forcing you to brake
Impatient drivers may pass without a safe gap or pull in front of you to avoid being stuck behind you, forcing you to brake. Watch for drivers who seem rushed.
Source: Ohio CDL Driver Manual, Section 2 (Drivers in a Hurry)
17. On a two-lane road carrying traffic both ways, where should the warning triangles go?
Correct answer: Within 10 feet of the vehicle, and 100 feet both behind and ahead
On an undivided two-way road, place a triangle within 10 feet of the vehicle to mark it, plus one 100 feet behind and one 100 feet ahead, on the shoulder or in your lane.
Source: Ohio CDL Driver Manual, Section 2 (Warning Device Placement)
18. When you pull over and stop at the roadside, where should the vehicle end up?
Correct answer: Parallel to the curb and clear of traffic, driveways, and hydrants
The vehicle should be parallel to the curb or shoulder and safely out of the flow of traffic, not blocking driveways, hydrants, intersections, or signs.
Source: Ohio CDL Driver Manual, Section 13 (Stop / Start)
19. For a first offense such as driving a CMV with a BAC of 0.04 or more, how long will you lose your CDL?
Correct answer: At least one year
A first major offense costs you your CDL for at least one year. That penalty grows to at least three years if you were hauling placarded hazardous materials.
Source: Ohio CDL Driver Manual, Section 1 (Disqualifications)
20. To measure your following distance in seconds, what should you do?
Correct answer: Count the seconds from when the vehicle ahead passes a landmark until you reach it
Wait until the vehicle ahead passes a fixed landmark such as a shadow or pavement mark, then count the seconds until you reach the same spot, comparing that to the length-based rule.
Source: Ohio CDL Driver Manual, Section 2 (How Much Space?)