As the name says, this truss carries Ohio Street, more specifically the ramps connecting Exit 50B to the downtown part of Ohio St. The rest of Ohio St. has no connection. I took this photo from the next bridge south across the North Branch Chicago River, Grand Ave.
If the Ohio St. ramps have button copy, you bet the mainline does. The WB ramps are actually fed from Ontario Street, the southern of four Great Lakes streets. Michigan Ave. runs north-south and partially defines the current and former shorelines of the eponymous lake, so it's excused.