Warning signs · W8-5
Slippery When Wet sign
Archive file: W08-05 Slippery When Wet/W08-05 Slippery When Wet 30x30.svg
FHWA public-use information
What it means
The surface may become unexpectedly slippery when wet.
Source: FHWA MUTCD — MUTCD 11th Edition with Revision 1 (December 2025), Section 2C.30, paragraph 01, PDF page 216.
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Meaning
Slippery When Wet warns of a surface that can become especially slick in wet conditions. Treat it as information about available grip, rather than just another reminder that it is raining. Your speed, following gap and use of the controls all matter on the affected section.
What to do
PennDOT recommends reducing speed and leaving a larger gap to the vehicle ahead. Avoid sudden braking or acceleration, and take turns very slowly. These are several parts of the same response: give yourself more room while making gentler demands on the tires.
Where it is used
Federal guidance places surface-condition signs before the affected road section, with additional signs where the condition continues. Start preparing when you receive the warning. The sign may identify a longer section, rather than a single slippery spot directly beside its post.
A sign to tell apart
Loose Gravel warns about loose material on the surface. Slippery When Wet warns about unexpected slipperiness. Both are surface warnings, but they identify different conditions; do not assume every grip warning means there is gravel on the road.
Practice with explanations
These are original learning questions based on the cited handbooks. Read each answer and its explanation below.
1. Rain begins on a Pennsylvania section signed Slippery When Wet. What should you do?
- Reduce speed and leave more following room.
- Drive closer to the vehicle ahead.
- Maintain speed and brake more sharply.
Answer: A. Reduce speed and leave more following room.
PennDOT calls for a lower speed and a larger following gap on this wet, slippery section.
2. How should you use the controls on a wet Pennsylvania road marked with this warning?
- Accelerate hard to keep the tires gripping.
- Brake and accelerate abruptly only on straight sections.
- Avoid quick braking and acceleration, and take turns slowly.
Answer: C. Avoid quick braking and acceleration, and take turns slowly.
Abrupt control inputs are unsuitable here. Reduce speed and use gentle inputs, especially when turning.
State source coverage
Handbook coverage and sample questions do not prove that a sign will appear on your exam. Even a published test scope cannot guarantee an individual exam question.
Pennsylvania
Handbook coverage
PennDOT explains this sign in its Pennsylvania Driver’s Manual. This is handbook coverage; it does not establish that this particular sign will appear on your Knowledge Test.
Pennsylvania permit sources · Practice with Pennsylvania questions
Federal sign and assembly options
The federal manual allows companion plaques identifying causes such as ice, a steel deck or excess oil. Read the plaque with the skidding-car symbol; the warning can identify a specific surface problem rather than wet pavement alone.
- Official source · MUTCD 11th Edition with Revision 1, Section 2C.30, paragraph 01 · PDF page 216 · Checked
State-specific variations have not been independently established for this study.
Verified question coverage
These free state-bank questions were independently verified. This does not establish complete state-bank readiness, app availability or what will appear on your permit exam.
California
1 free question uses this sign in Steerlet's verified question data.
California permit sources · General California permit practice (does not include this sign)
The linked 20-question permit quizzes do not currently include this sign.
Practice this sign in the federal 20-sign quiz. That tool uses MUTCD questions and is separate from the state-bank questions listed here.
This meaning is a federal MUTCD reference. Check your state's handbook for its rules and sign coverage; this page does not establish what appears on a state permit exam.
Try the free road sign quiz or find your state's handbook.
