Why do red lights have a flashing ring around them?

Question

Several of the red lights in a town I recently visited had white flashing rings around the actual red portion of the light. I was wondering if this was a defect in the light or does this actually serve a purpose?

Answer 1

So people on cell phones that are putting on makeup and eating a burger see the red light and dont kill people.

Answer 2

It is so you can identify the red light easier, also when fog is present.  Hope this helps !!

Answer 3

It reflects the light better so that it can be seen.......