St. Anthony Falls Bridge
Future I-35W Mississippi River Crossing
Minneapolis, MN

I-35W St. Anthony Falls Bridge

Northbound Span
• Structure ID: NBI 27410.
• Highway: I-35W (Northbound).
• Daily Traffic Count: 70,500 (2005).
 
Southbound Span
• Structure ID: NBI 27409.
• Highway: I-35W (Southbound).
• Daily Traffic Count: 70,500 (2005).
 
Statistics Common To Both Spans
• Location: River Mile 853.20.
• River Elevation: 725 Feet.
• Bridge Type: Post-Tensioned Precast Concrete Segment.
• Length: 1,216 Feet, 504 Foot Longest Span.
• Width: 90 Feet, 4 Inches (Per Span).
• Traffic Lanes: 5 Lanes (Per Span).
• Navigation Channel Width: 390 Feet.
• Height Above Water: 120 Feet (Estimated).
• Date Built: Opened September 18, 2008.
The original I-35W Bridge collapsed during rush hour on August 1, 2007. There were an estimated 100 vehicles on the bridge at the time of the collapse, with several motorists being fatally injured in the disaster. After the collapse, President Bush visited the site, and pledged money to rebuild the bridge. Congress fully funded the project by the end of December, 2007.

This web page covers the new bridge. For info and photos on the old I-35W bridge, please click here. For complete coverage of the bridge disaster, please click here.

The old bridge did not have a name. It has been referred to by its inventory number, Bridge #9430, or simply as The I-35W Bridge. The latter is a bit ambiguous since I-35W has two major river crossings in the Twin Cities area. The new bridge has been tentatively named the St. Anthony Falls Bridge, in recognition of its proximity to lower St. Anthony Falls, a major falls on the Mississippi River.

MN-DOT is working the project on a fast-track design-build plan. That is, parts of the bridge are still being designed while other parts are being built. The lead contractor is Flatiron. They won the bid despite submitting the most costly proposal.

Major construction began on October 29, 2007. The first noticeable work will include pile driving for the main piers on each side of the waterway, and building a huge casting basin. The casting basin will be used to cast the giant concrete piers and beams that will carry the larger spans of the bridge. MN-DOT is promised the people of Minnesota that the new bridge will be open on December 24, 2008. While that is doable, it certainly is what most would consider to be a stretch goal.

Update—in early May of 2008, the construction company, Flatiron, stated that they were more than half completed with the new bridge, and that it might be done as early as September or October. Flatiron has an internal goal of capturing all of the bonus money. Local officials would gain huge kudos if they could have the bridge open in time for the Republican National Convention scheduled for the first week of September.

Update—as of mid-July, 2008, the segments have been hoisted and the spans have been joined. For the first time, this huge construction site is starting to look like a bridge. Flatiron is running flat out, and is several months ahead of schedule. While it does not look like it will be open for the RNC, mid to late September looks realistic.

The new bridge opened on September 18, 2008. Motorists were allowed to start to queue up at 4:30 AM. A rolling blockage of State Patrol cars and MN-DOT trucks slowly crossed the bridge from both directions starting at 5:30 AM. In just a few minutes, the queue of cars waiting to cross completed their first journey across the bridge. From that point, the new bridge was officially open to traffic. West River Parkway would open to one lane traffic on September 29, 2008, and be fully open a week later.

The new St. Anthony Falls Bridge is an example of a modern post-tensioned segmental bridge. It is very interesting from a technical standpoint. It is not, however, a signature bridge from a design standpoint. As you roll across the structure, you hardly know that you are on a bridge. You cannot even see the river from the northbound lanes. Perhaps that is the highest compliment you can give to a structure like this. It does its intended job so well that you don't even know it is there.


I-35W St. Anthony Falls Bridge
I-35W St. Anthony Falls Bridge
I-35W St. Anthony Falls Bridge

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Photo and text by John A. Weeks III, Copyright © 2007, all rights reserved.
For further information, contact: john@johnweeks.com