GREEN BAY, WI (WTAQ)-Drivers on Green Bay's west side now have one less closure to deal with.  The Mason Street interchange is now open.  The interchange with Highway 41 opened this morning (SAT).  It has been closed for six months. The $29 million project replaced the overpass, and added three multi-lane roundabouts at the ramps, and the Taylor Street intersection.  It's part of the Highway 41 makeover stretching from Brown to Winnebago County.