What's on the Tennessee CDL General Knowledge Test? (2026 Guide)
Quick Answer: Questions, Passing Score, and Purpose
You'll get 50 multiple-choice questions on the Tennessee CDL general knowledge test, and I'd burn the number 40 into your brain because that's how many have to be right. That's an 80% score, so you can miss no more than 10. Tennessee follows this federal standard through Driver Services. That division is part of the Department of Safety & Homeland Security. Check tn.gov/safety for current testing and permit fees.
The CDL test Tennessee uses is the same in Nashville and Memphis. It's the same statewide. You'll take it at a DSD center, and you need to pass it before you can get your Commercial Learner's Permit, or CLP. Every Class A, B, and C applicant has to pass this one. No exceptions.
Topics Covered on the General Knowledge Test
The topics are not a secret. The questions come straight from the Tennessee Commercial Driver License Manual. That manual is your best friend. Read it. Then read it again.
These CDL general knowledge test questions come from the manual:
- Safe vehicle control and shifting
- Seeing hazards and communicating with other drivers
- Speed and space management
- Night driving
- Bad weather
- Mountain driving
- Railroad crossings and emergency handling
This one trips people up. Your pickup isn't going to teach you how a loaded tractor-trailer behaves, which is why they'll ask about stopping distance and off-tracking and what you do when the back end starts to skid. You'll also see questions on:
- Distracted driving
- Impaired driving
- Cargo basics
- Vehicle inspections
Cargo and inspections feel dull next to the mountain stuff, but I'd give them real time anyway, since a lot of those questions are about what you check and when you check it and have nothing to do with how good a driver you are.
Tennessee's terrain matters here. The TN CDL general knowledge test covers mountain driving. Anybody who's taken I-24 over Monteagle on the way from Nashville down to Chattanooga knows how long those grades feel with weight behind you, and I-40 through the Pigeon River Gorge out past Knoxville will throw curves and fog at you on top of that. The test won't ask you to name those roads. It asks how to handle a downgrade. Know your brake management and escape ramps.
How the Test Fits Into Getting Your Tennessee CLP
Getting your CLP in Tennessee is a process. Before you take the general knowledge test, you need a valid Tennessee driver license. You have to be at least 18 for intrastate driving, or 21 for interstate or hazmat. You also need a DOT medical exam and a Medical Examiner's Certificate.
Once you pass the test, you get your CLP. You have to hold it for at least 14 days before you can take the skills test. That's a federal rule. Some people think they can test the next week. You can't. Plan for that waiting period.
The way I explain it to new students, this test is the floor the whole CDL sits on, because without a pass there's no CLP and without the CLP there's no skills test later on. I'd get the DOT physical done early so the Medical Examiner's Certificate is already in your hand when you head to the DSD center, since nobody enjoys being told to come back another day. Give tn.gov/safety a look for the current details too, especially before you line up a school or a start date around that 14-day hold.
Endorsement Knowledge Tests You May Also Need
The general knowledge test is just the base. If you want certain endorsements, you'll take more knowledge tests on top of it. Common ones include:
- Combination vehicles
- Air brakes
- Tankers
- Doubles and triples
- Passenger
- School bus
- HazMat
HazMat also requires a federal TSA background check. That's not a DSD thing, it's federal. And it takes time. If you're thinking about hazmat, start early.
Every endorsement brings its own separate knowledge test along with it, so somebody going after a Class A with air brakes and doubles is really looking at a few exams and not one. If you're headed for a tractor-trailer job I'd start with combination vehicles and air brakes, then add the rest as the work calls for them.
You can practice for all of these with Drivio's free Tennessee CDL practice tests. They cover combination and air brakes too, not just the general knowledge part.
How to Prepare for the Tennessee CDL Knowledge Test
How do you actually prepare? Don't just read the manual once and walk in. That's how people fail. Here's a simple plan.
Start with the current Tennessee Commercial Driver License Manual. Read it in sections. I wouldn't try swallowing the whole thing the night before your appointment. Then drill practice questions. The Drivio free Tennessee CDL practice test is set up like the real thing. 50 questions. 80% to pass. Use it over and over.
After each practice round, look at what you missed. Don't just move on. Write down the topics. Master space management, braking, and inspection questions. Those show up a lot. Ten or fifteen minutes a day at the kitchen table, or in the truck on your lunch break, is plenty.
When you miss a space-management question, I'd go back and read that whole part of the manual, because the answer usually hangs on one detail about how much room a heavy truck needs at highway speed. Braking questions work the same way. Short sessions beat a four-hour cram. Use Drivio's free Tennessee CDL practice test until you score above 90%. Consistently.
Tennessee CDL Knowledge Test FAQ
How many questions are on the CDL general knowledge test? 50 questions. All multiple choice.
What score do you need? 80%. You need 40 correct out of 50.
How many can you miss? 10. Number 11 is the one that sends you home.
Is the test the same for Class A and Class B? Yes. All CDL classes take the same exam. Endorsement tests are separate.
Do you need endorsement tests? Only if you want those endorsements. Every CDL applicant must pass the general knowledge test.
Where do you take it in Tennessee? At a Driver Services Division center. You can sit the Tennessee CDL permit test at Driver Services centers around the state, and I'd look up the fees and hours on tn.gov/safety before you burn a morning driving there.
Common Questions From First-Time Tennessee CDL Applicants
How hard is the general knowledge test?
I'd call the Tennessee commercial driver's license test a good bit harder than the one you took for your car, mostly because they're so picky about wording. Two answers look right sometimes. The difference is often one word. "May" versus "must." People rush and read right past that word, so when you practice, stick close to how the manual actually phrases things.
How long should you study?
A week or two of studying every day works for most folks I talk to, and if you've never been around big trucks at all I'd give it longer than that.
What if you fail?
You can retake it. Tennessee allows retakes, but there may be a waiting period and a fee. Check with DSD. Before you go back, sit down with whatever you missed and actually fix it, or you'll just end up in the same chair with the same result.
Can you take it at 18?
Yes, for intrastate driving. Crossing state lines or hauling hazmat is a different story, and you'll have to wait till you're 21 for those.
Do you need ELDT before this test?
Entry-Level Driver Training applies before you take the skills test, not the knowledge test. You can take the general knowledge test first. But check current rules on tn.gov/safety.
How soon can you retake it?
It varies. Some states make you wait a day. Some longer. Confirm with DSD before you go.
Bottom line. The Tennessee CDL general knowledge test is predictable. 50 questions. 80% to pass. The topics are in the manual. Study it. Practice with Drivio's free Tennessee CDL practice test. Go in calm. You'll pass.
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