🔗Alabama Combination Vehicles — Question 6 of 10
What is the most common cause of a tractor-trailer jackknife?
Answer: B
Rear drive-wheel skid on the tractor
The most common cause of jackknifing is a rear drive-wheel skid on the tractor. The back of the tractor begins to move sideways during the skid and the weight of the trailer then pushes forward compounding the issue.
Source: Alabama CDL Manual
All choices
- AA skid on the front steering wheels
- BRear drive-wheel skid on the tractor
- CA trailer wheel skid
Alabama CDL Combination Vehicles Test Info
Questions on Exam
20
Passing Score
80%
Time Limit
Typically 30 minutes; varies by testing location
Age Requirements
Intrastate: 18+ · Interstate: 21+
Alabama Law Enforcement Agency (ALEA)
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More CDL Combination Vehicles Practice Questions
- Glad hands are usually connecting which of these?
- Why should you lock the tractor glad hands to each other (or dummy couplers) when you are not towing a trailer?
- After connecting the air lines but before backing under the trailer you should:
- The crack-the-whip effect is related to:
- Sudden turns or aggressive braking will have the greatest effect on which trailer?