I-39 was developed as a connector route between the tollways in northern Illinois and the network of Interstate highways in central Illinois. The state started building I-39 in two pieces, first working from Rockford and heading south, and then from Bloomington and heading north. At that time, the Illinois River Bridge was not approved or funded, so it would be a gap in the highway. Washington politics came into play, and the bridge was finally approved as a demonstration project, despite the fact that the proposed bridge did not use any new technology that needed to be demonstrated. I-39 was built in the late 1980s and was completed in Illinois by 1993. It was extended north into central Wisconsin on existing freeways. The interchanges around Rockford were rebuilt during the mid-2000s. Today, the route is used as an outer bypass of the Chicago area, especially by long-haul truckers.
The Lincoln bridge is a conventional tied-arch design. It uses a large steel arch with suspension cables to support the roadway over the main span, which is 620 feet in this case. The arch is flanked by over a mile of steel girder bridge that is elevated about 60 feet above the river valley. The approaches are built as two independent bridge spans, but they join into one bridge span to cross the main river channel.
At the time the bridge was built, the contractors requested and were granted permission to take a short-cut by not removing the wood that was used as concrete forms when installing the concrete deck. This decision turned out to dramatically shorten the life of the structure. The wood held water, and caused key steel connections to rust, and it caused the concrete to rot. By the mid-2000s, the only choice was to strip the bridge down to it girders and rebuild the traffic decks. The net result is a $30-million repair bill for a bridge that is less than 20 years old.
The top photo was taken from the location of the old townsite of Shippingsport. The Abraham Lincoln bridge is the large green arch in the background. The old Illinois Central Railroad bridge is in the middle, and the new IL-351 bridge is in the foreground.
The next 6 photos show a typical bridge crossing heading north to south. Due to the construction, the southbound lanes are set up for two-way traffic, and southbound traffic is confined to a single narrow lane on the far right side of the bridge.