Use this guide to review common traffic-signal meanings and the sign shapes California DMV expects drivers to recognize on the written knowledge test.
QUICK ANSWER
The California DMV written test expects you to recognize both traffic signals and sign shapes. A flashing red signal means stop, then proceed when safe. A five-sided sign warns that you are near a school. A diamond-shaped sign warns of a specific road condition or danger ahead. Railroad approaches may use a yellow-and-black circular sign or X-shaped sign.
STUDY NOTES
Traffic signals
- Solid red: stop. A right turn may be allowed after a complete stop when no sign prohibits it and the turn can be made safely.
- Red arrow: stop and do not turn until a green signal or green arrow allows movement.
- Flashing red: stop, then proceed when safe.
- Yellow signal: the light is changing; stop if you can do so safely.
Learn sign shapes as well as colors
- Five-sided sign: school area; slow down and watch for children.
- Diamond-shaped sign: warning about a road condition or danger ahead.
- White rectangular sign: communicates rules you must obey.
- Yellow-and-black circular sign or X-shaped sign: railroad crossing warning.
Use the official sign chart
DMV also publishes a Road Sign Chart (DL 37) in its Additional Testing Materials. Use that chart when you want a concentrated visual review of signs rather than relying on memory from text descriptions alone.
PRACTICE CHECKS
Check your understanding
Answer each question before opening the explanation.
1. What does a flashing red traffic signal mean?
Show answer
Answer: Stop, then go when it is safe.
DMV treats a flashing red signal like a stop requirement before proceeding.
2. What does a diamond-shaped road sign usually indicate?
Show answer
Answer: A warning about a specific road condition or danger ahead.
The handbook identifies diamond-shaped signs as warnings.
3. What does a five-sided sign indicate?
Show answer
Answer: You are near a school.
The handbook uses the five-sided shape for school warnings.
FAQ
Common questions
What does a flashing red light mean in California?
Stop. After stopping, you may proceed when it is safe.
What does a diamond-shaped traffic sign mean?
It warns of a specific road condition or danger ahead.
What shape is a school warning sign?
The California Driver's Handbook identifies a five-sided sign as a school warning.
Where can I study official California road signs?
California DMV publishes sign examples in the Driver's Handbook and a Road Sign Chart (DL 37) in its Additional Testing Materials.
VERIFY THE RULE
Official sources
This study page was reviewed against the DMV material below. Open the source when you want the complete rule, exceptions, or surrounding context.
Last reviewed: August 16, 2026 · Reviewed by Master My Test