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California road sign CW1-4R — Construction warning for single lane shift to the right

MUTCD CW1-4R · Work zone signs

Construction warning for single lane shift to the right

What it means

Construction warning for single lane shift to the right.

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 CW1-4R.)

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

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