Given that Minneapolis is a major trading area for western Wisconsin, and the population boom underway on the Wisconsin side of the state line, the I-94 river crossing is a major transportation facility important for the economy of both states. Traffic is high, especially on holiday weekends.
Looking at the top photo, which is shot from the Wisconsin side facing Minnesota, notice the small jog in the highway at the base of the bridge. I-94 in Wisconsin once was aligned on the current east bound lanes, and crossed the river where the south span currently sits. The old south span was a long through-truss bridge. In the mid-1980's, Minnesota completed I-94 from the state line to I-494/694. This project included adding the current north span. Once that span was completed, the old bridge was shut down and refurbished, opening again in the late 1980's. With I-94 aligned along the old span, the new bridge introduced a small jog in the highway alignment.
Wisconsin DOT rebuilt I-94 from the state line to about 3 miles east of Hudson in the late 1980's. The new eastbound lanes were built south of the existing right of way, and the westbound lanes were built on the old alignment. This had the effect of making the jog even bigger.
Next came the flood of 1993. The old south span was severely damaged in the record flood. The state made temporary repairs, but the stress on the structure caused hundreds of cracks to form in the steel. The bridge was no longer able to handle heavy loads. On an emergency basis, eastbound trucks were routed across the median and on the inside lane of the westbound span. Had this action not been taken, bridge engineers expect that the old span would have ended up in the water within a year. They consider it a close call.
Work on a new south span was started in 1994. The new bridge was built between the existing bridges. It was tricky work since the new bridge was 80 feet wide, but the existing bridges were only 95 feet apart. The new bridge opened up only 363 days after it was started, which is an amazing feat of bridge construction. Just as the new south span was completed, the north span required significant deck work. As a result, all traffic was routed across the new south span for nearly a year. The net effect is that this area was under construction for most of a decade.
Many people are aware that the Mississippi River forms part of the border between Wisconsin and Minnesota. As a result, many people traveling I-94 towards the Twin Cities mistakenly think that they are crossing the Mississippi River via this bridge, and are unaware that the Saint Croix River also forms part of the border between these two states.
