Warning
MUTCD W8-5
Slippery When Wet Sign — Meaning
- Category
- Warning
- Shape
- Diamond
- Colors
- Yellow, Black
- Text
- (skidding car symbol)
- MUTCD Code
- W8-5
What does the Slippery When Wet Sign mean?
The Slippery When Wet sign is a yellow diamond showing a vehicle skidding on a curve. It warns drivers that the road surface ahead becomes especially slippery when wet, due to road materials, drainage issues, or surface treatments.
-
1
Reduce speed when the road is wet
-
2
Avoid sudden braking, accelerating, or steering
-
3
Increase following distance behind other vehicles
-
4
Watch for hydroplaning during heavy rain
-
5
Apply brakes gently and steer smoothly
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On bridges (which freeze before regular roads) -
In tunnels with poor drainage -
On metal grate decks -
Where road surface is unusually smooth or polished
Slippery surfaces are most dangerous in the FIRST 10 minutes of rainfall, when oil and grime mix with water before being washed away. Drive especially carefully right after rain begins.
Why are some roads more slippery than others when wet?
Smooth road surfaces, metal grates, painted markings, and oil-soaked pavement all become slick when wet. Bridge decks freeze faster because they have no ground heat.
What should I do if I start to skid?
Take your foot off the accelerator and steer smoothly in the direction you want to go. Do not slam the brakes — that worsens the skid.
Are tires more important on slippery roads?
Yes — tread depth determines water displacement and grip. Worn tires hydroplane at much lower speeds. Check tread regularly, especially before wet seasons.
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