Heading north on I-75? You'll run into Zilwaukee Bridge construction

Apr 5, 2013

Start your calculations and predictions... will three lanes over the Zilwaukee Bridge be enough? Or are you better off taking a different route?

Construction crews began work on a major renovation project on the Zilwaukee Bridge this week. The project is expected to last through January 2015.

Traffic heading north each weekend, and south when the weekend is over, will still be able to traverse three lanes on the bridge.

Traffic is being rerouted along as follows:

Wednesdays - Saturdays

  • I-75 North will continue across the bridge
  • I-75 South will be detoured onto I-675

Sundays - Tuesdays

  • I-75 South will shift onto I-75 northbound lanes and over the bridge
  • I-75 North will be detoured onto I-675

Here's a map of the detours and the other I-75 construction projects nearby:

Construction projects and detour routes for the I-75 Zilwaukee Bridge.
Construction projects and detour routes for the I-75 Zilwaukee Bridge.
Credit MDOT

MDOT says work on the bridge includes "replacing bearings, bridge deck overlay and barrier repairs, and electrical work."

Southbound bearing replacement, including the road and bridge work project, begins April 1 and continues through January 2014. Northbound bearing replacement will begin after work on the southbound lanes is completed, and is expected to last through January 2015. Total investment: $36 million.

Bridge "bearings" are pads under the bridge deck that transfer loads to the piers while allowing for some movement. They look like this:

A view from under a bridge. See the pad? That's a 'bearing.'
A view from under a bridge. See the pad? That's a 'bearing.'
Credit Washington DOT

According to Michigan Highways, MDOT engineer Matthew Chynoweth says the bearings for the Zilwaukee Bridge are getting worn out. New bearings of "high-density plastic material" will give the bridge a much longer life:

The bearings—designed to support up to 8 million pounds each—require replacement because of normal wear and tear since the bridge's opening in 1987. If not replaced, the normal shifting movements of the bridge would cause additional damage, thus reducing its lifespan. Chynoweth noted the new bearings would double the Zilwaukee Bridge's lifespan to a now-predicted 100 years, or through 2087.

The bridge project, along with other nearby bridge and highway projects, are expected to cost $70 million.

I say we go back to these days and watch the boats go by:

The OZB (the original Zilwaukee Bridge).
The OZB (the original Zilwaukee Bridge).
Credit Michigan Highways