US50 in Illinois between O'Fallon and Carlyle has several orphaned bridges.
Originally planned to be I-64 in the original 1955 highway plan. When the I-64 route was pushed south, IDOT retained funding to build US50 to interstate standards to Lake Carlyle (IL-127)
The buildout was delayed by the 1973 oil shocks and finally build out was funded in 1976. While under construction, IL was wooing the Mitsubishi Group to build a plant in Normal IL.
Chrysler, who was Mitsubishi's platform partner wanted better access between Normal and the plant in Belvidere.
So what was left of the US50 funding was moved to seed the building of I-39 from Rockford to just over the Illinois River.
So US50 has all of these built new but never used bridges along the ROW. Abandoned lanes and ramps exist in certain places as well.
Ever since then the local politicians have been trying to get US50 back on the 4 lane wagon with IDOT without much luck.
There was an environmental study funded in FY2015 to update the 1973 version which had expired. It is unknown if the bridges, having sat for 40 years with no use and no maintenance are even viable. Many believe they will eventually be torn out when IDOT has the funding to finish the road planned.