What does wait for green mean?

Maybe its just reminding you that red means stop and green means go.

so no one runs the light? Hey, it says wait for green; damn.

The sign is instructing you to wait for a green light before driving. These are often placed at busy junctions to remind drivers that jumping the gun by even a second or two (and driving at the amber light) can result in an accident, because of the tight nature of the light switchover at such junctions.

First off “Wait for green” != No turn on Red (tired of people who don’t get this part).
You can still prudently turn right on red.

It is a warning that the the electrically timed intersection may often give the green to the opposing side so don’t jump the gun just because they are going.