Can Someone Tell Me Why This Sign is Necessary at This Portland Traffic Light?

A traffic light at the corner of Commercial and Beach Streets has a sign posted that gives instructions to drivers that, to me, seems like it's unnecessary.

You know there are some not-so-bright drivers anytime you see one of these signs on the road. Because of them, the DOT had to be put up signs because they don't remember simple rules of the road. Let's zoom in shall we?

What am I missing here? Am I not understanding the language on this sign correctly? This is common sense isn't it? If a light is red, you wouldn't enter the intersection right? Were too many people running the light and this is the official way to tell people not to? I just don't know.

Before I saw this sign, another sign was the one I thought was the most unnecessary sign in Portland.

Of course if people will drive around gates that are down then they're probably willing to risk stopping on railroad tracks putting themselves in danger of being hit by a train as well. So this sign had to go up.

I'm still stumped on the "Enter Intersection on Green Signal Only" sign though.

Have you seen any road signs that you think are completely unnecessary? Let us know in the comments or on our Facebook page.