If you look @ StreetView, you see an 'Business M-60 END' shield there from '07 all the way till at least
Oct '13. After that, it turned into an
'END M-60' shield (obliviously an error, as at the intersection, it's a Business shield still).
And on a side note, probably also recenter 'MI51_S' between 11th & 12th Street, due to it being a split carriageway there.