Free Ohio CDL practice test online
Take a free Ohio CDL practice exam online with clear explanations—no sign-up. Coverage includes general knowledge, vehicle systems, combination vehicles, cargo, and endorsements. Then verify current requirements with Ohio Bureau of Motor Vehicles.
Ohio Bureau of Motor Vehicles gives the general knowledge test as 50 questions, and federal law sets the bar at 80% correct on every knowledge test. You must also hold a commercial learner’s permit for 14 days before the skills test.
New to the knowledge test? CDL endorsements explained · One-week study plan
Requirements before you test
Ohio CDL test requirements
Commercial licensing is largely federal. Any figure above credited to a 49 CFR section applies in every state — see 49 CFR 383.135(a)(1) and 49 CFR 383.25(e). A figure credited to Ohio Bureau of Motor Vehicles is Ohio’s own, and may be stricter than the federal floor. Test length, fees, and scheduling are set by Ohio Bureau of Motor Vehicles (official source).
Entry-Level Driver Training comes first
Since February 7, 2022, a new Class A or Class B CDL, a class upgrade, or a first passenger, school bus, or hazardous materials endorsement requires training from a provider on the FMCSA Training Provider Registry (49 CFR 380.600). Practice questions are study material and do not satisfy that requirement.
FMCSA Training Provider RegistryYou need a Ohio licence first
A commercial learner’s permit only counts if you already hold an ordinary licence from the same state (49 CFR 383.25(a)(2)). The Ohio non-commercial knowledge test runs 40 questions and needs 30 correct, with permits issued from age 15 years, 6 months.
Ohio permit practice testWhat you will practice
Build coverage topic by topic.
Each question carries a topic, difficulty, explanation, and source section so your review has context.
Sample questions
5 Ohio CDL practice questions
Try these Ohio sample questions now — each shows the correct answer with a plain-language explanation and a source section. The full 600-question bank is in the practice run.
1. On a long downgrade, safe speed depends on:
- AOnly whether ABS is equipped
- BOnly the number of trailers
- COnly the posted speed limit
- Total weight, length and steepness of the grade, road conditions, and weather
Answer: Total weight, length and steepness of the grade, road conditions, and weather. Select and maintain a speed that fits all of those factors; never exceed a posted maximum safe speed for the hill.
Source: Commercial Driver License Manual — Driving safely — speed on downgrades
2. You should turn a speed retarder off when:
- AClimbing a long hill in dry weather
- The road is wet, icy, or snow-covered because it can skid the drive wheels
- CYou are empty
- DABS is equipped
Answer: The road is wet, icy, or snow-covered because it can skid the drive wheels. Retarders brake the drive wheels when you lift off the accelerator. Poor traction plus retarder force causes skids.
Source: Commercial Driver License Manual — Vehicle systems — retarders
3. Rearward amplification in a combination means a quick steer input at the tractor can:
- AAlways stabilize the rear
- Cause a much larger swing at the rear trailer
- CEliminate the need for mirrors
- DReduce rollover risk
Answer: Cause a much larger swing at the rear trailer. The “crack-the-whip” effect is why doubles/triples and long combinations need gentle steering.
Source: Commercial Driver License Manual — Combination vehicles — rollover / stability
4. Converter dollies required to have ABS show a yellow lamp on:
- AThe tractor dash only
- The left side of the dolly
- CThe pintle hook
- DEach tire valve
Answer: The left side of the dolly. Dollies built on or after March 1, 1998 must have ABS; look for the left-side malfunction lamp.
Source: Commercial Driver License Manual — Doubles and triples — ABS on dollies
5. Black ice is dangerous because it is:
- A thin clear layer that can make the road look merely wet
- BOnly present above freezing
- CHarmless to commercial tires
- DAlways bright white and obvious
Answer: A thin clear layer that can make the road look merely wet. Whenever the temperature is below freezing and the road looks wet, watch for black ice.
Source: Commercial Driver License Manual — Driving in winter — identifying slippery surfaces
CDL knowledge areas
Classes and endorsements, organized.
Each area below scopes the reviewed question bank to one knowledge test. The material is federal, so it applies in Ohio just like everywhere else — the endorsement guide explains how the codes fit together.
The foundation for commercial driving: inspections, space, speed, communication, hazards, and safe operation.
- Pre-trip inspection
- Space and speed management
- Railroad crossings
- Emergency procedures
Understand air-brake components, inspections, warning devices, stopping distance, and controlled braking.
- Dual air systems
- Low-air warnings
- Brake lag and fade
- Applied-leak and static checks
Prepare for safe coupling, inspection, turning, backing, and handling of tractor-trailer combinations.
- Fifth-wheel inspection
- Coupling and uncoupling
- Off-tracking
- Trailer skid prevention
Study hazard communication, shipping papers, placards, loading rules, parking, and emergency response responsibilities.
- Hazard classes
- Placards and labels
- Shipping papers
- Loading and segregation
Learn how liquid surge, outage, bulkheads, and high centers of gravity change vehicle handling.
- Liquid surge
- Outage requirements
- Smooth braking
- Rollover prevention
Practice converter-dolly inspection, coupling order, rearward amplification, and stability principles.
- Coupling sequence
- Converter dollies
- Rearward amplification
- Space management
Prepare to inspect, load, and operate buses while keeping passengers, aisles, and exits safe.
- Vehicle inspection
- Passenger loading
- Emergency exits
- Prohibited practices
Review student loading, danger zones, mirrors, emergency procedures, and special railroad-crossing duties.
- Danger zones
- Student loading
- Mirror use
- Railroad crossings
More midwest practice
Nearby CDL practice tests
Jump to another midwest state hub, or browse every jurisdiction.
Common questions
What this practice can—and cannot—tell you.