State transportation officials say 85 percent of the work required to complete fabrication of the retrofit brace for supporting part of the Zilwaukee Bridge carrying I-75 over the Saginaw River is now complete.

It's estimated another three weeks will be needed to conclude the fabrication process with installation taking another two to four weeks. That means it could be late September or early October before the project is finished.

Work on the brace for the north bound side of the bridge began after construction workers accidentally cut through support steel while trying to replace bridge bearings.  Engineers spent a couple of months designing a retro-fit for the north span before work began this summer on fabricating the brace.

Last week northbound traffic was shifted to the southbound span to ease the flow of vacation travel for the balance of the summer and the Labor Day weekend.  Southbound I-75 traffic is detoured around the bridge by way of I-675.  The process will be reversed  during the holiday weekend in time for traffic returning home from northern Michigan on Sunday and Labor Day.