^Westbound trailblazer at Interstate 55 in Shorewood, February 2022.
US Route 52 runs east-west across northern Illinois, diving southeast through Joliet and Kankakee to cross into Indiana from east-central Illinois. It runs from Savanna, Illinois east and southeast to Mendota, then more or less due east again, then from Joliet, it heads southeast to Kankakee and beyond. US Route 52 doesn't always run east-west, though! US Route 52 is overall a diagonal route, running from northwestern North Dakota to Charleston, South Carolina (see the national page for more on that).
US Route 52 and Iowa State Route 64 cross the Mississippi River into Savanna, Illinois from the island city of Sabula, Iowa (Iowa State Route 64 becomes Illinois Route 64 at this point)...
The bridge over Mississippi River deposits US Route 52 and Illinois 64 at a T-intersection with Illinois 84, and the two routes join Illinois 84 south:
Having passed through Savanna, US Route 52 and Illinois 64 send Illinois 84 to split south:
In Mount Carroll, US Route 52 and Illinois 64 continue east together through a junction with Illinois 78: