Georgia CDL Permit Practice Test​: Combination Vehicles

Coupling and Uncoupling Procedures

This is where many people miss questions. Not because it’s hard, but because the steps have to be in the right order. Order matters.

Start with the fifth wheel. In real life, you might be doing this at a busy yard outside Macon with trucks rolling by, but on the Combination Vehicles permit test the focus is inspection and secure connections. Look for cracks, missing bolts, and anything that keeps the fifth wheel from locking correctly. Also check the platform is greased and the jaws aren’t damaged. Simple checks. Big consequences.

Air lines and electrical connections come next. Don’t rush. On the road around Columbus or Sandy Springs, a loose line can become a dangerous failure fast. You’ll want to know how to spot worn glad hands, damaged seals, and kinked lines. The test likes “must” language here, not “maybe.”

• Inspect air and electrical lines for wear, leaks, and secure mounting
• Make sure the trailer height is correct before backing under it
• Confirm the locking jaws are fully closed around the kingpin
  This one trips people up.

After coupling, you verify. Always. The tug test is a common topic because it proves the connection is holding. You’ll also be expected to know to raise landing gear fully and secure the handle, then check that the air lines won’t snag during turns. Think about tight turns in Roswell or Johns Creek. That’s where mistakes show up.

Uncoupling is the same idea in reverse. Secure the trailer. Chock if needed. Lower landing gear to support the trailer. Then disconnect air and electrical lines carefully and stow them so they don’t drag. Finally, release the fifth wheel and pull out slowly. Slow is smooth.

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Preventing Skid and Rollover in Combination Vehicles

Rollover prevention is mostly about speed and balance. That’s it. But the DDS questions often hide the lesson inside a scenario. You’ll see a curve, a ramp, or a lane change. Then you choose what keeps you upright.

Speed management is the headline. In Georgia, faster-than-posted speeds are common on interstates, especially around Atlanta and the I-285 Perimeter. But in a combination vehicle, “keeping up with traffic” is not a safety plan. Curves and ramps are where rollovers happen, and they happen fast. Very fast.

Load and weight distribution matter too. A high center of gravity makes a trailer more likely to tip, and uneven loading can cause sway. If the load is heavier toward the rear, you may feel a whipping effect, especially during quick steering inputs. Don’t yank the wheel. Gentle inputs.

Skids are about traction and braking. Rain comes down hard in Georgia, and hydroplaning is real on I-75, I-20, and GA 400. If your wipers are on, headlights should be on. That’s Georgia law. The test may not ask it directly in this section, but it’s part of safe operation. Know it.

• Slow before curves and off-ramps, not during them
• Keep a steady following distance to avoid panic braking
• Watch for shifting loads that change how the trailer tracks
  This one trips people up.

Also, remember what causes trailer skid versus drive wheel skid. Trailer skid can push you sideways. Drive wheel skid can make you lose steering control. The right answer often depends on which wheels are slipping. Read the prompt twice. Time pressure makes you misread.

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Test Format and Passing Requirements

You’re preparing for a written knowledge exam through the Georgia Department of Driver Services. DDS is looking for safe, repeatable decision-making. Not guesses.

The Combination Vehicles permit test is part of your CDL knowledge testing. The number of questions can vary, but the structure is consistent: multiple choice, one best answer, and lots of “what should you do first” style wording. First. That word matters.

Passing is based on a minimum score requirement set by DDS, and most drivers do fine when they practice with purpose. Use each missed question as a clue about what to review. Don’t just memorize. Understand.

Expect questions on coupling order, checking for secure lockup, air line connections, and what to do if something doesn’t feel right during the tug test. You may also see rollover scenarios involving speed on ramps, especially with top-heavy loads. In places like South Fulton where traffic can force sudden merges, the test wants you thinking ahead, not reacting late.

Here’s how to use this georgia cdl permit practice test​ effectively: take it once to see your weak spots, then retake it slowly and explain each answer to yourself. Out loud. Sounds silly. Works.

If you’re aiming to pass the Combination Vehicles permit test, focus on the small words: may vs must, before vs after, and safest vs fastest. Those tiny differences decide points. And points decide passes.