I was on IL 146 this past weekend and work for two new eastbound lanes was underway from the Emerson Bridge to IL 3. Current state varied from culvert work to having some base rock down.
This route is supposedly part of a longer Cape Girardeau to Murphysboro expressway:
http://www.dra.gov/pdfs/transportation/6.%20Illinois.pdf (http://www.dra.gov/pdfs/transportation/6.%20Illinois.pdf)
EDIT:Full Delta Development Highway System maps (scroll to bottom of page):
http://www.dra.gov/programs/transportation/ (http://www.dra.gov/programs/transportation/)