SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/drive-advisory-speed-plaque

Under a yellow curve warning sign, a small yellow sign says 25 MPH. What is it?

An advisory speed, the recommended safe speed for the curve.

  1. The new speed limit
  2. A minimum speed
  3. The recommended speed for the curve ✔

Why: A yellow speed plaque under a warning sign is advice, not the legal limit. It is the speed engineers recommend for that curve in good conditions.

Huh, didn't know that: An advisory speed plaque is never used alone; it always goes with a warning sign.

The dad joke
Why did the curve get a speed sign? It wanted drivers to take it easy on it.
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References

Answer: The recommended speed for the curve. A yellow speed plaque under a warning sign is advice, not the legal limit. It is the speed engineers recommend for that curve in good conditions.

  1. MUTCD 11th Edition with Revision 1, Section 2C.59 mutcd.fhwa.dot.gov/pdfs/11th_Editionr1/mutcd11theditionr1hl.pdf
    may be used to supplement an advance warning sign to indicate the advisory speed for a condition.
    Checked 2026-10-09.
  2. MUTCD 11th Edition with Revision 1, Section 6H.32 mutcd.fhwa.dot.gov/pdfs/11th_Editionr1/mutcd11theditionr1hl.pdf
    plaque shall not be used in conjunction with any sign other than a warning sign, nor shall it be used alone.
    Checked 2026-10-09.

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