Hydroplaning occurs when tires ride on a thin film of water instead of on the surface of the road. To prevent hydroplaning in rainy weather, you should:
- Put on your cruise control to maintain a constant speed.
- Decrease your speed. ✓
- Move to the shoulder of the road as soon as it starts to rain.
Answer: B. Decrease your speed.
To prevent hydroplaning in rainy weather, you should decrease your speed.
Why this is the answer
The handbook explains that in wet or rainy conditions a vehicle can ride on water because the tires lose contact with the road, and a slight change of direction, braking, or a gust of wind can send it into a skid. Its first instruction for avoiding hydroplaning is to drive slowly, and it also says to slow down if you hear sloshing from the tires and when changing lanes or direction. Lower speed is the action the handbook ties directly to keeping the tires in contact with the road.
Why the other answers are wrong
- A. Put on your cruise control to maintain a constant speed. — Holding a steady speed with cruise control does not slow you down, and the handbook's guidance for wet roads is to drive slowly.
- C. Move to the shoulder of the road as soon as it starts to rain. — The handbook tells you to drive slowly and steer around standing water, not to pull onto the shoulder when rain begins.
Remember it
When water is on the road, think of your speed first: slow down, and ease off gradually rather than braking suddenly if you start to hydroplane.
Official handbook: California Driver Handbook (DL 600), Section 8: Safe Driving, p. 62