Why does highway I-180 exist? A steel mill was proposed to be built in the city of Hennepin. The steel would be a vital product to the national economy. Roads would have to be upgraded to carry the heavy loads to bring materials into the mill and haul finished product to market. After a study, it was determined that road upgrades would be cost prohibitive. A new highway would be needed. Illinois did not have highway funds available, but federal Interstate highway money was available. So, a superhighway was built the 12 miles from I-80 to the Hennepin steel mill, complete with a nearly mile long bridge over the Illinois river and a stack interchange with highway IL-29.
As a reader, you can probably guess the rest of the story. The new steel mill went out of business in an economic downturn shortly after it opened. The mill has changed hands several times, and only started back into operation in 2002. It runs at a much lower volume than it was built for, so the highway upgrades never were needed.
Prior to I-180 being built, IL-26 crossed the Illinois River at Hennepin. It was crossed on a huge metal monster bridge that featured a 3-span through truss connected back to back with a 2-span through truss. The designation for highway IL-26 was moved to share the I-180 bridge in 1990. The old bridge continued to deteriorate until it became a hazard. The state of Illinois attempted to sell the old bridge, but no takers had the wherewithal to refurbish the structure to make it safe. As a result, the old bridge was removed in 2000.
The loss of the old Hennepin Bridge was felt by bicyclers. There are regional trails on both sides of the river, but bicycles are not allowed on the I-180 bridge (due to its interstate status). With the IL-26 bridge gone, the nearest alternative is a 30 mile detour.
