Fog hides the road, rain makes it slick and can lift your tires off it, and floodwater can sweep a car away. Slow down early, use low beams, and never drive into water over the road.
If you must drive in fog:
- Reduce speed so you can stop within the distance you can see, even if that's only a few feet
- Turn your headlights on low beam to avoid glaring reflection
- Look for road edge markings to guide you
- If you can barely see, pull off the road, stop, and use emergency flashers until it clears
Know the rule
Creeping along at 5 or 10 miles an hour in thick fog is dangerous; pull off instead.
Handbook p. 117 ↗Know the rule
Wet roads can be as dangerous as icy roads. Reduce speed: you'll need more distance to stop and may skid if you turn sharply.
Handbook p. 117 ↗Know the rule
Roads are most dangerous at the start of a light rain, when road oil and water mix into a greasy film.
Handbook p. 117 ↗Know the rule
Keep wipers and defroster in good condition, turn on your headlights, signal all turns and begin braking well in advance so others know your plans.
Handbook p. 117 ↗Hydroplaning in most cars
| Speed | What happens |
|---|---|
| 30 to 40 mph | Hydroplaning may begin |
| 50 to 60 mph (bad rainstorm) | Tires may lose all contact with the road |
Know the rule
With no road contact there's no friction for braking, accelerating or cornering; a gust of wind, a curve or a slight turn of the wheel can cause a skid.
Handbook p. 117 ↗To reduce the chance of hydroplaning:
- Slow down during rainstorms
- Replace tires as soon as they become worn
- Keep tires properly inflated
Know the rule
Never attempt to drive across a flooded roadway. The road beneath may be washed out, and floods are especially dangerous at night.
Handbook p. 118 ↗Floodwater
| Depth | Danger |
|---|---|
| 6 inches | Can float some small cars |
| 2 feet | Will carry away most vehicles |
Know the rule
Nearly half of U.S. flash flood deaths are people trapped in vehicles. If your vehicle stalls in floodwater, leave it immediately and seek higher ground.
Handbook p. 118 ↗Put it into practice
Heavy rain has water flowing across a dip in the road ahead. It doesn't look deep, but six inches can float some small cars. Turn around and find another route.