Driving combination vehicles safely
Section 6.1 of the Kentucky CDL Manual (p. 6-1) covers the risks of driving combination vehicles, such as rollover, jackknife and off-tracking. It is tested on the Combination Vehicles test.
Key facts
| Part of | the Combination Vehicles test (80% to pass) | KY CDL Manual, front section pp. 2-3 |
|---|---|---|
| Manual section | §6.1 Driving combinations safely | KY CDL Manual p. 6-1 |
| Questions in CDL Mile's bank | 22 | CDL Mile, checked against KY CDL Manual |
Key rules
- § 6.1.6p. 6-3
Swing the front end wide enough that the rear wheels clear the curb, but keep the rear close to it. That leaves no room for other drivers to slip past you on the right during the turn.
Turn Wide
- § 6.1.6p. 6-3
Steer wide enough that the rear wheels clear the curb, but keep the rear of the rig close to it. If you must use another lane, swing wide as you complete the turn; swinging left before the turn lets drivers pass you on the right.
Turn Wide
- § 6.1.1p. 6-1
A full load sits higher and raises the center of gravity. The manual says a fully loaded rig is ten times as likely to roll in a crash as an empty rig.
Rollover Risks
- § 6.1.1p. 6-1
The more cargo is piled up, the higher the center of gravity sits above the road, and a high center of gravity makes a truck easier to roll. That is why cargo should be kept as low as possible.
Rollover Risks
- § 6.1.1p. 6-1
Keep cargo as close to the ground as you can, centered on the rig and spread out. A high load, or one that makes the trailer lean to one side, makes a rollover more likely.
Rollover Risks
Try two questions
Combination Vehicles · Driving combinations safely
You are pulling a set of doubles on an unlit rural highway at night. How should you choose your speed?
Tap an answer to see the explanation and the manual page.
Combination Vehicles · Driving combinations safely
How does the stopping distance of a large combination vehicle change when it is empty instead of fully loaded?
Tap an answer to see the explanation and the manual page.
More Combination Vehicles topics
Sources
Kentucky Commercial Driver's License Manual, version March 2025, Kentucky State Police. Page references are to its printed page numbers. CDL Mile is independent and not affiliated with Kentucky State Police.
Updated for the March 2025 Kentucky CDL manual. Last checked November 5, 2026.
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