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California road sign R10-18a — Traffic signal violations are photo enforced

MUTCD R10-18a · Regulatory signs

Traffic signal violations are photo enforced

What it means

Indicates that traffic signal violations are photo enforced.

What to do about it

It is a regulatory sign: it states a law you must obey, not a suggestion. Ignoring it is a citable violation. (MUTCD R10-18a.)

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 regulatory signs series — the ones most easily mixed up with it.

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