I think most people have “conveniently” forgotten what that means… I have witnessed several instances locally that the lights end up “RED BLINKING” and most drivers just do not pay attention or do not care? They may tap their brakes but keep moving is the rule of the day.
Here is what I found on a search – even though I knew it, someone else saying it means I was not wrong…
From Wikipedia
Alternating alternates (flashing lights)
In the United States, the color alone indicates traffic flow. Flashing red is the equivalent of a stop sign. Flashing amber indicates that the opposing traffic may enter the intersection at any time and drivers should exercise caution.
From answers.com: In: Rules of the Road [Edit categories]
“And Now the Rest of the Story – “What the HELL does a flashing RED light signal!!!!