Michigan Highways

The Zilwaukee Bridge

Page Contents: Top | Zilwaukee Bridge Report | Aerial Imagery | Additional Information

The best, most concise description of the Zilwaukee Bridge can be found in an MDOT-produced publication from the early-1990s:

The Zilwaukee Bridge is a...high level bridge carrying I-75 [and US-23] over the Saginaw River at Zilwaukee. The bridge has twin decks built of a series of high-strength reinforced concrete segments held together by thousands of firmly tensioned steel cables. The mile-and-a-half long bridge replaces an outmoded, inadequate drawbridge that caused backups on the freeway every time it opened for river traffic.

Zilwaukee Bridge photo, courtesy MDOT.Of course, for many Michiganders, the Zilwaukee Bridge evokes a response harkening back to a major construction accident while bridge was not yet half completed in the early-1980s which added many millions to the cost and years to the completion. However, let's step back in time to the genesis of the crossing in the first place.

The origin of today's Zilwaukee Bridge can be traced back to the original two-lane highway bypass on the east side of the City of Saginaw completed in 1953. Prior to that, all through traffic in the Saginaw area was funnelled through downtown via US-10 and US-23. In the early-1950s, the Michigan State Highway Department constructed a new eastern bypass of Saginaw for through US-23 traffic, beginning at the existing route (Dixie Hwy) in Bridgeport, continuing northerly to meet back up with US-23 (present-day M-13) northeast of the city. While no Saginaw River crossing seems to have been planned at that time, the 1953 bypass would become part of a much bigger project later in the decade.

With the coming of the Interstate Highway System in the late-1950s, the earlier two-lane highway of Saginaw was incorporated into the new Interstate highway running from Detroit to the Mackinac Bridge. In 1960, the first portion of the new route in the Saginaw area was opened to traffic. It consisted of the new four-lane, double-leaf bascule (draw) bridge and a freeway beginning at the northern end of the 1953 bypass (at present-day M-13), crossing the bridge and continuing northerly toward Bay City. This was part of the I-75/US-10/US-23 freeway. By the end of the next year, the original 1953 US-23 bypass had also been converted to full freeway with overpasses and interchanges at the intersecting roads.

While it may have seemed like a good idea in the late-1950s, soon after the opening of the (original) Zilwaukee Bridge in 1960 it became clear the crossing would cause more problems then it solved. While the most obvious problems concerned the massive traffic tie-ups on the freeway each time the bridge opened, it also caused problems for traffic on the Saginaw River as well. The bridge was only 150 feet wide and several ships actually hit the bridge, causing damage and additional tie-ups on the freeway as well. Top top it off, shipping traffic actually quadrupled in the years after the bridge was completed and the back-ups on the freeway reached three to four hours in duration. The worst back-ups, of course, occurred during major holiday weekends and during the fall hunting season.

Less than fifteen years after the original bascule bridge was opened, the decision came to replace it with a high-level bridge. This only after other ideas had been batted around, including a tunnel under the river and reconstructing the newly-completed I-675 loop through downtown as the through route. The final bridge design selected and constructed is a post-tensioned, segmental, box girder bridge and work on the new structure commenced in late-1979 and was projected to cost approximately $77 million (not counting approaches and ramp work).

As noted above, when the bridge was approximately half-complete, a major construction accident halted all work in August 1982. Much more on the accident, what caused it and what was done to remedy the situation can be found in Section 4: The Accident in The Zilwaukee Bridge: From the Beginning.

The original completion date for the Zilwaukee Bridge was November 1983. However, due to the accident and its subsequent repair work, construction on the bridge did not resume until late 1984 under a new contract with a new contractor. On Tuesday, September 22, 1987 the final 117-ton piece of concrete was installed on the bridge and the northbound lanes of the I-75/US-23 freeway were routed over the bridge for the first time on Wednesday, December 23, 1987—a nice Christmas present, four years after the bridge was to be completed. Almost exactly nine months later, the southbound side of the bridge was opened to traffic on Monday, September 19, 1988. The original bascule bridge was permanently closed on that date—but only to automobile traffic. The bridge operator continued to staff the bridge until it was removed so that river traffic would not be impeded. According to a story posted to the USENET newsgroup alt.great-lakes the deck of the old drawbridge now rests on the bottom of Lake Huron as a fish habitat.

While the bridge has performed very well in the years since it has opened to traffic, the bad news did not stop even after motorists had been using the span for more than a year. While the remaining ramp connections were being completed at either end of the new bridge, it was discovered one of the unfinished ramps crossed a buried landfill contaminated with PCBs. In an August 22, 1989 article, The Detroit Free Press noted "Containing and removing the toxic polychorinated biphenyl will cost at least $100,000 and could delay completion of the ramp, now scheduled to open this year."

 

The Zilwaukee Bridge: From the Beginning

In May of 1987, the Michigan Department of Transportation issued a report detailing the background of the Zilwaukee Bridge, the details on the accident and the attendant repairs as well as a discussion of the safety of the bridge, which was a major concern with the public at the time. That report has been reproduced on this website in its entirety for informational purposes and can be found at the following link. (Please remember while reading the report, it was issued prior to the completion of the bridge and is worded accordingly.)

The Zilwaukee Bridge: From the Beginning

 

Aerial Imagery

 

Additional Information