Ohio CDL Combination Vehicles Practice Test

The Ohio CDL Combination Vehicles test is a multiple-choice knowledge test you take for your commercial learner's permit. You need at least 80% to pass. That's the federal minimum in 49 CFR 383.135 (Ohio does not publish its own number).

Last updated Oct 15, 2026. FirstTry CDL is a CDL permit test prep site by Hive Asset Group, LLC.

By Scott Wilder, Editor

Last reviewed against the Ohio CDL manual on October 15, 2026

Scott Wilder on X | scottwilderhq.com

FirstTry CDL is a CDL permit test prep site by Hive Asset Group, LLC. It offers free exam-style practice tests built from the official CDL manual. FirstTry CDL is not affiliated with any DMV, FMCSA or government agency. Practice questions are exam-style questions built from the official CDL manual, not actual test questions.

Ohio CDL permit facts

What	What Ohio says	Source
Combination Vehicles pass mark	At least 80%. This is the federal minimum (49 CFR 383.135); Ohio does not publish its own number.	Official page
CLP fee	$31.50 (listed as the CDL temporary permit fee, driver fee included)	Official page
CLP validity	12 months	Official page
Test languages	Drivers must read, speak and write English well enough to talk with the public, understand highway signs and answer official questions. Translation aids are not allowed. The BMV offers the CDL manual in English (HSY 7605) and Spanish (HSY 7606). Tests are taken in person at a driver exam station.	Official page

20 question Combination Vehicles practice test

1. How often should you drain each trailer air tank?
1. A. Once a week
2. B. Every day
3. C. Once a month
4. D. Only when the brakes feel weak
Show answer
Answer: B. Every day
Draining daily keeps water and oil from building up.
From the official CDL manual, section 6.2.6.
2. How fast should you drive a combination vehicle at night?
1. A. At the posted limit, since the headlights are on
2. B. Fast enough to keep up with traffic
3. C. Slowly only when the road is wet
4. D. Slowly enough to see obstacles in time to change lanes or stop gently
Show answer
Answer: D. Slowly enough to see obstacles in time to change lanes or stop gently
Your headlights should show hazards early enough for a smooth reaction.
From the official CDL manual, section 6.1.2.
3. According to the manual, what makes rollovers happen?
1. A. Turning too fast
2. B. Driving too far from the shoulder
3. C. Using the foot brake too early
4. D. Having a full fuel tank
Show answer
Answer: A. Turning too fast
Rollovers happen when you turn too fast, so slow down for corners and ramps.
From the official CDL manual, section 6.1.1.
4. How does looking far down the road help you in a combination vehicle?
1. A. It lets you follow other vehicles closer
2. B. It lets you take curves faster
3. C. It helps you avoid surprises and sudden lane changes
Show answer
Answer: C. It helps you avoid surprises and sudden lane changes
Seeing far ahead keeps you from being surprised and having to change lanes suddenly.
From the official CDL manual, section 6.1.2.
5. Before coupling, how should the jaws of the fifth wheel be?
1. A. Closed
2. B. Locked on a shank
3. C. Greased and closed
4. D. Open
Show answer
Answer: D. Open
The manual says the fifth wheel jaws must be open for coupling.
From the official CDL manual, section 6.4.1.
6. When you check the upper fifth wheel, what should you see about the glide plate?
1. A. It is securely mounted to the trailer frame
2. B. It is mounted to the tractor frame
3. C. It is mounted to the trailer axles
Show answer
Answer: A. It is securely mounted to the trailer frame
The glide plate must be securely mounted to the trailer frame.
From the official CDL manual, section 6.5.1.
7. What is off-tracking?
1. A. The trailer drifting out of its lane on a straight road
2. B. The rear wheels following a different path than the front wheels in a turn
3. C. The trailer skidding when brakes lock
4. D. The tractor leaning in a high-speed turn
Show answer
Answer: B. The rear wheels following a different path than the front wheels in a turn
The manual calls this off-tracking or "cheating."
From the official CDL manual, section 6.1.6.
8. Which two jobs does the emergency (supply) line do?
1. A. Carries the foot brake signal and controls the hand valve
2. B. Supplies air to the trailer air tanks and controls the emergency brakes
3. C. Supplies air to the trailer tanks and carries the foot brake signal
4. D. Controls the parking valve and drains the tanks
Show answer
Answer: B. Supplies air to the trailer air tanks and controls the emergency brakes
These are the two purposes the manual gives.
From the official CDL manual, section 6.2.4.
9. Turning right at a corner, why should the rear of your rig stay close to the curb?
1. A. It gives the trailer more room to off-track
2. B. It keeps the trailer wheels from skidding
3. C. It keeps the trailer lights visible to drivers behind
4. D. It stops other drivers from passing you on the right
Show answer
Answer: D. It stops other drivers from passing you on the right
Keeping the rear close to the curb keeps other drivers from squeezing past on the right.
From the official CDL manual, section 6.1.6.
10. You are fully loaded and approaching a curved off ramp. What lowers your rollover risk?
1. A. Slow down and drive the ramp slowly
2. B. Keep highway speed because ramps are gentle
3. C. Brake hard in the middle of the curve
4. D. Change lanes quickly to line up with the ramp
Show answer
Answer: A. Slow down and drive the ramp slowly
Rollovers happen when you turn too fast, so drive slowly on ramps.
From the official CDL manual, section 6.1.1.
11. Your truck has ABS. May you follow other vehicles more closely?
1. A. Yes, ABS always stops the truck sooner
2. B. No, ABS does not allow closer following
3. C. Yes, but only on dry roads
Show answer
Answer: B. No, ABS does not allow closer following
ABS will not let you drive faster, follow closer, or drive less carefully.
From the official CDL manual, section 6.3.2.
12. When does a large combination vehicle take longer to stop?
1. A. When it is fully loaded
2. B. The stopping distance is the same either way
3. C. When it is empty
4. D. Only when the trailer is loaded and the tractor is empty
Show answer
Answer: C. When it is empty
An empty combination takes longer to stop than a fully loaded one.
From the official CDL manual, section 6.1.3.
13. You shut the engine off to hear the trailer brakes. When do you start it again?
1. A. Before you apply and release the trailer brakes
2. B. After you back under the trailer
3. C. After you raise the landing gear
4. D. When you are sure the trailer brakes are working
Show answer
Answer: D. When you are sure the trailer brakes are working
The manual says to start the engine when you are sure the trailer brakes are working.
From the official CDL manual, section 6.4.1.
14. During the air flow check, what do you use to provide air to the service line?
1. A. The red trailer air supply knob
2. B. The tractor parking brake
3. C. The trailer handbrake
Show answer
Answer: C. The trailer handbrake
The trailer handbrake provides air to the service line.
From the official CDL manual, section 6.5.2.
15. What do you do with the wheel chocks in the last step of coupling?
1. A. Leave them under the trailer wheels
2. B. Throw them on the ground behind the trailer
3. C. Hang them on the landing gear
4. D. Remove them and store them in a safe place
Show answer
Answer: D. Remove them and store them in a safe place
The last step is to remove the wheel chocks and store them in a safe place.
From the official CDL manual, section 6.4.1.
16. The manual says to avoid quick lane changes, especially in what condition?
1. A. When the rig is fully loaded
2. B. When the rig is empty
3. C. When the road is dry
Show answer
Answer: A. When the rig is fully loaded
Quick lane changes are most risky when the rig is fully loaded.
From the official CDL manual, section 6.1.1.
17. What do relay valves do for the trailer brakes?
1. A. They let the trailer brakes apply more quickly
2. B. They lock the trailer brakes for parking
3. C. They fill the trailer tanks
4. D. They close the air-lines
Show answer
Answer: A. They let the trailer brakes apply more quickly
Relay valves on the service line let the trailer brakes apply faster.
From the official CDL manual, section 6.2.4.
18. Which pair of actions best helps prevent a rollover in a combination vehicle?
1. A. Stack cargo high to spread the weight and drive slowly around turns
2. B. Keep cargo as low as possible and drive slowly around turns
3. C. Keep cargo low and hold your speed steady through turns
4. D. Load to one side and drive slowly around turns
Show answer
Answer: B. Keep cargo as low as possible and drive slowly around turns
Low cargo and a slow speed in turns are the two things the manual names for preventing rollover.
From the official CDL manual, section 6.1.1.
19. In Step 11, how far do you raise the landing gear to test the connection?
1. A. All the way up
2. B. Not at all
3. C. Halfway up the legs
4. D. Slightly off the ground
Show answer
Answer: D. Slightly off the ground
Step 11 says to raise the trailer landing gear slightly off the ground.
From the official CDL manual, section 6.4.1.
20. Which two names are other names for the trailer hand valve?
1. A. Relay valve and trolley valve
2. B. Johnson bar and cut-out cock
3. C. Trolley valve and Johnson bar
4. D. Dolly valve and Johnson bar
Show answer
Answer: C. Trolley valve and Johnson bar
The manual lists trolley valve and Johnson bar as other names for the trailer hand valve.
From the official CDL manual, section 6.2.1.

Ohio CDL Combination Vehicles questions

What score do you need to pass the Ohio CDL Combination Vehicles test?

You need at least 80% to pass. That is the federal minimum in 49 CFR 383.135. Ohio does not publish its own number.

Is the Ohio CDL Combination Vehicles test the same as other states?

The Combination Vehicles test is built on the same federal knowledge standards in every state, so the topics match the CDL manual. Ohio uses its own handbook: https://dam.assets.ohio.gov/image/upload/publicsafety.ohio.gov/HSY7605.pdf

How much does a CDL permit cost in Ohio?

CLP fee: $31.50 (listed as the CDL temporary permit fee, driver fee included).

What languages is the Ohio CDL knowledge test offered in?

Drivers must read, speak and write English well enough to talk with the public, understand highway signs and answer official questions. Translation aids are not allowed. The BMV offers the CDL manual in English (HSY 7605) and Spanish (HSY 7606). Tests are taken in person at a driver exam station.

Sources

https://www.ecfr.gov/current/title-49/section-383.135
https://www.bmv.ohio.gov/doc-fees.aspx
https://www.bmv.ohio.gov/dl-cdl-classes.aspx
https://dam.assets.ohio.gov/image/upload/publicsafety.ohio.gov/HSY7605.pdf
Manual sections used in this test: 6.1.1; 6.1.2; 6.1.3; 6.1.6; 6.2.1; 6.2.4; 6.2.6; 6.3.2; 6.4.1; 6.5.1; 6.5.2

Combination Vehicles practice test in nearby states