Oklahoma Combination Vehicles Test
If you've ever felt your trailer get pushed sideways by a gust on I-40 west of El Reno, you know why this test matters.
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This is the Oklahoma Combination Vehicles test. You need 16 out of 20 to pass — it covers coupling, stability, and wind handling on roads like I-35.
Key Topics
- •Coupling steps in the right order
- •Wind and rollover on I-40 and I-35
- •Jackknife prevention on ice and hills
About the Oklahoma Combination Vehicles Test
Topics Covered
- ✓Coupling and uncoupling procedures — Oklahoma examiners drill into the exact order because you'll often hook up on uneven gravel lots at oil fields. Miss a step and the trailer drops.
- ✓Trailer stability and rollover prevention — I-40's crosswinds and the curves on I-35 through the Arbuckles make this critical. A loaded trailer can tip if you take a ramp too fast.
- ✓Jackknife causes and prevention — Ice on I-44 near Tulsa or sudden wind gusts on US-287 in the Panhandle can lock your trailer. Know how to avoid the skid.
- + 3 more topics
📘 Study Tips & State Info
First, get the coupling sequence memorized. Oklahoma examiners do not let you skip a step. They want you to say it in order: inspect, back under, connect air and electrical, raise landing gear, test. Practice it out loud while you're driving your personal vehicle — it sounds dumb but it works.
Second, think about Oklahoma weather. The manual says 'reduce speed in high winds.' That means when you see dust blowing across I-40 near Sayre, you drop to 45 mph. The test will ask you about wind effects on trailer stability. If you've never driven in a 40-mph gust, imagine your steering wheel fighting you. That's the context.
Third, the Oklahoma CDL manual has a section on driving on downgrades. Yes, we have some — the Arbuckle Mountains on I-35 south of Davis. Know the proper gear and brake use. The test will ask about brake fade. Don't ride your brakes. Use engine braking.
The Oklahoma CDL written tests are administered by Service Oklahoma (formerly DPS). You'll take the Combination Vehicles test at any Service Oklahoma driver license exam office that offers CDL testing. Major locations include Oklahoma City (NE 36th St), Tulsa (Memorial Dr), Lawton, and Enid. Appointments are strongly recommended — walk-ins wait hours, if they get in at all.
You must pass the General Knowledge test first. Then you can add endorsements like Combination Vehicles. Bring your Medical Examiner's Certificate, proof of identity, and residency documents. The fee for the written test is included in your CDL permit application ($44.50 as of 2025). If you fail, you can retake it the next business day at the same office.
Oklahoma does not require a separate skills test for the Combination Vehicles endorsement — it's part of your Class A road test. But you have to pass the written knowledge test before you can get your CLP, and you need the CLP to practice on public roads.
About the Oklahoma Combination Vehicles Test
The Combination Vehicles endorsement is required for every Class A CDL applicant in Oklahoma. If you plan to pull a trailer — whether it's a tanker full of crude out of the Permian Basin or a grain hopper on I-44 — you need to pass this test. It covers coupling and uncoupling, trailer stability, jackknife prevention, and the specific handling challenges of driving an articulated truck on Oklahoma roads.
Oklahoma isn't flat and boring. The crosswinds on I-40 between Weatherford and Elk City can shove a 53-foot trailer into the next lane if you're not ready. Ice storms shut down I-35 in the Arbuckle Mountains every winter. And if you're hauling oil field equipment on county roads near Woodward, you're dealing with tight turns, soft shoulders, and loaded trailers that shift weight fast. The test covers all of that.
The Oklahoma CDL test follows federal standards — 20 multiple-choice questions, 80% to pass. The state adds its own emphasis on secure coupling because of the rough terrain many of you will park on. Know the sequence cold, understand how trailer length affects off-tracking in roundabouts (Oklahoma has more of them now), and you'll be fine.
Topics Covered
Study Tips
First, get the coupling sequence memorized. Oklahoma examiners do not let you skip a step. They want you to say it in order: inspect, back under, connect air and electrical, raise landing gear, test. Practice it out loud while you're driving your personal vehicle — it sounds dumb but it works.
Second, think about Oklahoma weather. The manual says 'reduce speed in high winds.' That means when you see dust blowing across I-40 near Sayre, you drop to 45 mph. The test will ask you about wind effects on trailer stability. If you've never driven in a 40-mph gust, imagine your steering wheel fighting you. That's the context.
Third, the Oklahoma CDL manual has a section on driving on downgrades. Yes, we have some — the Arbuckle Mountains on I-35 south of Davis. Know the proper gear and brake use. The test will ask about brake fade. Don't ride your brakes. Use engine braking.
Oklahoma Specific Information
The Oklahoma CDL written tests are administered by Service Oklahoma (formerly DPS). You'll take the Combination Vehicles test at any Service Oklahoma driver license exam office that offers CDL testing. Major locations include Oklahoma City (NE 36th St), Tulsa (Memorial Dr), Lawton, and Enid. Appointments are strongly recommended — walk-ins wait hours, if they get in at all.
You must pass the General Knowledge test first. Then you can add endorsements like Combination Vehicles. Bring your Medical Examiner's Certificate, proof of identity, and residency documents. The fee for the written test is included in your CDL permit application ($44.50 as of 2025). If you fail, you can retake it the next business day at the same office.
Oklahoma does not require a separate skills test for the Combination Vehicles endorsement — it's part of your Class A road test. But you have to pass the written knowledge test before you can get your CLP, and you need the CLP to practice on public roads.