CDL General Knowledge TestCombination Vehicles (if applicable)Easy
A driver is preparing to back a combination vehicle into a dock. To minimize the risk of 'jackknifing', what is the most important principle to follow?
- AKeep the tractor and trailer perfectly straight at all times.
- BMake small steering adjustments and use mirrors frequently.
- CBack up as quickly as possible to get the maneuver done.
- DUse the trailer hand valve to control trailer speed.
Show answer & explanationAnswer & explanation
Correct answer: B. Make small steering adjustments and use mirrors frequently.
Making small steering adjustments and constantly checking mirrors allows a driver to detect and correct minor deviations before they become major jackknifing situations.
Why the other options are wrong
- A. It is nearly impossible to keep them perfectly straight throughout a backing maneuver, especially when turning.
- C. Backing quickly increases the risk of jackknifing and reduces reaction time to correct errors.
- D. Using the trailer hand valve during backing can lock the trailer wheels, causing a jackknife.
Backing Combination Vehicles
Techniques for safely backing a combination vehicle, minimizing jackknife risk.
- Small steering inputs are key.
- Frequent mirror checks are essential.
- Go slow to allow for corrections.
Memory trick: Slow and steady, mirrors bright, keeps your backing always right.