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What role does speed play in most jackknife situations?
- A.Excess speed for the conditions is behind most of them, because it forces the hard braking that locks wheels
- B.Speed has no connection to jackknifing; only brake defects cause it
- C.Jackknifes happen more often at parking-lot speeds than at highway speed
- D.Higher speed prevents jackknifing by keeping the trailer stretched out
Correct answer
A. Excess speed for the conditions is behind most of them, because it forces the hard braking that locks wheels
Why
Nearly every jackknife chain starts with needing to slow faster than traction allows, and that need grows with speed. Driving at a speed suited to the surface is the single biggest jackknife prevention measure.
Manual topic: Combination Vehicles - Skids and Jackknifing · From the Combination Vehicles practice bank (CV-154).