It means you need to slow down and look for cross-traffic. Why? Because usually when you have a flashing yellow the cross-street will have a flashing red, which works the same as a stop sign. Similarly to stop signs, if they don't see you coming they'll pull out in front of you.
The LAW: http://leginfo.legislature.ca.gov/faces/…
(a) Flashing red (stop signal): … driver shall stop at a clearly marked limit line … the driver may proceed subject to the rules applicable after making a stop at a stop sign.
(b) Flashing yellow (caution signal): When a yellow lens is illuminated with rapid intermittent flashes, a driver may proceed through the intersection or past the signal only with caution.
Green light= proceed with caution. Yellow light = be prepared to stop. Red light = Stop.
A flashing yellow light = be prepared to stop. A flashing red light = Stop, then proceed with caution.
It means the traffic signals are not operating.
Treat the intersection as uncontrolled. Use extra caution and normal give way rules to determine who has right of way.
treat a flashing yellow light like a stop sign
Slow down and catch the red light and be safe.
slow down I believe