My first thought when I saw the picture of that road sign was: "WTF?" I do finally believe that I understand the lane, but I'd have been one confused driver had I been confronted with that sign for the first time while actually out driving.
I don't know whether I'd use the lane or not. I'd have to be there in person to really decide. But the fact that such a complicated road sign is needed is a big, red-flag to me.