Interstate 35W (Minnesota)

I-35W is prone to heavy-rain event flooding in several areas, intersecting both natural habitats, including the Minnesota Valley National Wildlife Refuge between Burnsville and Bloomington, and the dense urban areas through the city of Minneapolis. In the great 1965 Minnesota River flood, the highway was underwater in the floodplain wetlands south of the Minnesota River bridge at Burnsville.[3][4] Dikes have been constructed, and the highway has been raised since then.[5] The storm sewer system under I-35W in the urban core of south Minneapolis has also been cited as a place prone to flashfloods during rain events. Improvements continue to be made to this area as part of future projects.[6][7]

I-35W Bridge over Minnesota River

When the Minnesota River bridge between Burnsville and Bloomington was completed in 1960, it was two lanes in each direction. I-35W, at the time, only extended as far south as MN 13 in Burnsville. Improvements were made in 1984 to redeck and widen the bridge, but subsoil problems found at the north end resulted in the new lanes being temporarily closed. In 1989, the lanes were opened as high-occupancy vehicle lanes when the Minnesota Department of Transportation (MnDOT) expanded the north approach to carry the additional traffic.[8][9]

On August 1, 2007, the I-35W Mississippi River bridge in Minneapolis collapsed into the Mississippi River around 6:05 pm CDT, killing 13 people and injuring 145.[10] The metal arch bridge had a length of approximately 1,900 feet (580 m) and a roadway height of over 100 feet (30 m) above the river. The bridge connected Minneapolis southwest of the Mississippi River to the Northeast Minneapolis neighborhood and served residents in the northern suburbs of the metro area.[11][12][13] Because of the collapse of the bridge, I-35W traffic was temporarily detoured through eastbound I-94 to northbound MN 280 where it meets up with I-35W in Roseville.

The replacement I-35W Saint Anthony Falls Bridge was built in less than a year and opened to traffic on September 18, 2008, at 5:00 am CDT, three months ahead of schedule.[14][15][16]

A preconstruction photo of the Crosstown Commons junction. The two left lanes are I-35W northbound, while MN 62 enters via the ramp on the right.

The Crosstown Commons was one of the most congested traffic interchanges in Minnesota. While it is sometimes referred to as an intersection, it is a one-mile (1.6 km) merger or concurrency of I-35W and MN 62. The layout is not a typical intersection: there is only a single level of roadbed and it creates a dogleg in I-35W. This shared right-of-way intersection for I-35W and MN 62 has been a topic of political debate for many years. As originally built, there were only six lanes on the commons, and all drivers merging from one highway to the other are required to change at least one lane as they merge and then diverge again. The name comes from the fact that MN 62 is also known locally as the Crosstown Highway.

The project to improve the interchange began in May 2007 after bids were received in April 2007. The new interchange features three throughlanes for I-35W in both directions, ending at 42nd Street, and two separate throughlanes for MN 62 in each direction, eliminating the need to weave across traffic. The cost of correcting the deficiencies in that short stretch of highway was estimated to be $285 million (equivalent to $364 million in 2021[17]).[18][19]

In 2004, the City of Minneapolis threatened to withhold municipal consent for the project unless new bus lanes and bus stations were included.[20] Lake Street currently has a bus station at grade with I-35W on both sides. Eventually, the project was altered to include the desired additional bus access. The bid was won by the Ames, Lunda, and Schafer consortium for the 2007 cost of $288 million (equivalent to $368 million in 2021[17]). The project included 25 new bridges, 63 lane miles (101 km) of highway, and expanded the total roadway width from six lanes to 12 lanes at Lyndale Avenue. The bridges were cast in Coates and trucked in for onsite erection. The new design includes transit/HOV lanes and was completed in November 2010.[21]

The 35W@94 Downtown to Crosstown Project was a construction project to repave and reconfigure I-35W and I-94. The work took place from 15th Street to 43rd Street on I-35W, and I-94 from Portland Avenue to 3rd Avenue in Minneapolis. The project added a southbound entrance at County Road 3 (Lake Street), added a northbound exit to 28th Street, reconstructing and widening frontage roads to accommodate new ramps. HOV lanes using E-ZPass replaced the dynamic shoulder lanes in the center of the freeway. Retaining walls, noise barriers, and bridges being replaced throughout the entirety of the project. The METRO Orange Line uses a new station at Lake Street, and a bus-only transit ramp on 12th Street connecting I-35W to downtown. The entire project was completed in September 2021.[22]