July 16, 2008: East end of US 54 in western Illinois. It used to go to Chicago; a piece that doesn’t stick closely to the interstates is still IL 54. US 36 was signed as the freeway route and I-72 was added later, but there are significant stretches where it could be returned to the two-lane route.
The “54” is normal size. The others are jumbo for interstates, although this is the intersecting road. Illinois puts its name on its state route shields (has to, with Indiana’s also being square) but not the interstates.