Slippery When Wet Sign
Name: Slippery When Wet
Category: Roadway Related
Group: Roadway Surface Condition
Color: Yellow with black symbol of a skidding car
Posted: Where unexpected slippery conditions may exist
Slippery When Wet is one sign that often appears on the written knowledge tests in United States. It is also a quite common sign on our roads and highways. Make sure you understand its meaning.
The Meaning of the Sign
The sign tells you to be prepared for a slippery roadway. A part of the roadway you are on may be slippery even when the rest of the pavement is dry and safe.
In general, this slippery condition occurs in cold or wet weather conditions and often on bridges and overpasses.
The Slippery When Wet sign may be used to warn of unexpected slippery conditions.
When used, it should be placed in advance of the beginning of the affected section, and additional signs should be placed at appropriate intervals along the road where the condition exists.
Why do You See the Sign Near Bridges?
Pay attention when you pass a bridge the next time. You are highly likely to see the Slippery When Wet sign close to the bridge.
Bridges and overpasses simply freeze more quickly when temperature drops and therefore become more slippery. Bridges and overpasses also dry out last. So, even when the rest of the roadway seems fine, an overpass can hide spots of ice in winter.
The reason is that bridges and overpasses don’t keep heat as well as highways. The highway takes advantage of the insulation and warmth from the soil under the pavement. It loses heat only from the surface, while a bridge is surrounded by cold air and loses heat from both above and below. When it loses heat, it also cools down much quicker.
Concrete and asphalt are also poor conductors of heat, which lessens the rate of heat loss from a roadway.
Slippery When Wet is a Warning Sign – Slow Down
Remember, the yellow background color means it is a warning sign and it is posted there for a reason.
When it is raining, snowing, or temperature is close to freezing, you should always approach a bridge or overpass with care.
The basic speed law in your state requires you to adjust your speed to current conditions, including weather and roadway conditions. So, just let up on the gas pedal a bit before you get to the bridge and avoid sudden moves and hard braking on the bridge when weather is bad. Fast or sudden maneuvers may throw your vehicle into a skid.
You should also watch your following distance to vehicles ahead of you. It takes longer to stop on a slippery pavement, so don’t follow others too closely. In case of a rear-end crash, you are most likely to be found at fault.
Bridge Ices Before Road
Sometimes you will see this sign in winter: Bridge Ices Before Road.
It has the same meaning as the Slippery When Wet sign but emphasizes icy conditions in winter. The sign may be covered or removed during summer months.
You may also see the Slippery When Wet sign with the supplemental ICE plaque to warn you especially of the risk of ice in a highway area.
There might, of course, be other reasons for a slippery pavement.
The same Slippery When Wet sign is used in those situations, but often with a supplemental plaque to inform you of the reason for why the slippery conditions might be present.
Examples of such plaques are “ICE”, “STEEL DECK”, and “EXCESS OIL”.
Rainfalls also make a pavement slippery, especially when it just starts raining after a period of dry weather. This is because oil and dust have not yet washed away.
If it starts to rain on a hot day, the pavement can be very slippery because the heat has caused oil in the asphalt to come to the surface.
In areas where a wet pavement causes more trouble than normal, this may be emphasized with the “WET” plaque beneath the Slippery When Wet sign.
Slippery When Wet Sign on the DMV Test
Pay special attention to the Slippery When Wet sign and the Winding Road sign. Studies show that many first-time test takers mix them up .
Try these questions: