Day Two Hundred Forty Two

This just made me laugh.  While driving through Chicago I saw this stop sign below a stop light.  It made me think of the goofy jokes they used to tell back in the old days :)  You know:

"Who's on first."
"I don't know. Who?"
"That's what I just said! Who's on first!"

I could just see a goofy skit with this.  I received different answers on what this is for: pedestrians, for when the stop light goes out & they need it to be a stop sign.....I don't know!