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California road sign W10-9P — Supplemental plaque for no train horn warning

MUTCD W10-9P · Warning signs

Supplemental plaque for no train horn warning

What it means

Supplemental plaque for no train horn warning.

What to do about it

It is a warning sign: the yellow diamond warns of a condition ahead so you can slow down and be ready before you reach it. (MUTCD W10-9P.)

Practice this on the real test format

Signs are the part of the DMV written test people fail on, because reading them is a skill rather than a fact to memorize. Aprobify drills all 1034 of them, and tells you why each answer is what it is.

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Sign designations follow the MUTCD and the California MUTCD published by Caltrans; meanings are checked against the California Driver's Handbook (DL 600, rev. 6/2025). Edited by Fernando Aguilera. Aprobify is not affiliated with the California DMV.

Signs in the same family

These sit next to it in the warning signs series — the ones most easily mixed up with it.

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