Home › CDL Practice Tests › General Knowledge Questions › Question 93
At what speed can hydroplaning begin, and what increases the risk?
- A.It can begin around 30 mph, sooner with standing water, worn tires, or low tire pressure
- B.Only above 70 mph
- C.Only with brand-new tires
- D.It cannot happen to heavy trucks
Correct answer
A. It can begin around 30 mph, sooner with standing water, worn tires, or low tire pressure
Why
On water-covered pavement, tires can start riding on a film of water at about 30 mph, and in deeper water a heavy truck's tires can lose contact entirely at highway speed. Slowing down in standing water is the only prevention.
Manual topic: Safe Driving - Wet Weather Driving · From the General Knowledge practice bank (GK-093).