^Westbound trailblazers leaving the Interstate 57 interchange, a bit north of Cairo. February 2023
Illinois Route 3 is the westernmost north-south route In Illinois, stretching from East St. Louis south to Cairo, and it is never far from the Mississippi River. Its northern end curls northwestward out of Alton to run in the uplands near Elsah and Grafton, placing Illinois 3's ultimate northern terminus at Illinois 100 in Grafton. The south end is at US Route 51, which connects to Cairo, near Urbandale.
Illinois 3 gets its start in Grafton, heading northeast into the uplands, from Illinois 100 and the Mississippi River...
Illinois 3 heads east to meet the southern end of Illinois 109...
At Godfrey, Illinois 3 is joined by Illinois 111 which comes from the north, and both routes head east under US Route 67...
At an interchange where Interstate 55 meets Interstates 64 and 70 in East St. Louis, a scattered collection of ramps provide access to Illinois 3; at this disorganized interchange, Illinois 3 joins Interstates 55 and 64 southwest...
Just on the east side of the Poplar Street Bridge carrying Interstates 55 and 64 into St. Louis, Illinois 3 diverts southerly onto its own roadway again...
In Cahokia Heights, Illinois 3 meets the western end of Illinois 157...
Illinois 3 is strictly a surface road from here until the end, and it crosses Illinois 156 in Waterloo:
At Red Bud, an easterly Illinois 3 turns back toward the south, as Illinois 159 starts out going north and Illinois 154 starts out going east (picture taken from the south):
At Ruma, Illinois 3 meets the eastern end of Illinois 155...
In Chester, Illinois 3 joins Illinois 150 west for a couple blocks:
Then, Illinois 3 splits from Illinois 150 to continue south out of Chester:
Illinois 3 heads more east-southeasterly, catching the southern end of Illinois 151:
West of Murphysboro, Illinois 3 meets the western end of Illinois 149:
West of Jonesboro, Illinois 146 joins Illinois 3 south:
Illinois 146 then splits from Illinois 3 to head west, to the bridge over the Mississippi River into Cape Girardeau, Missouri:
After passing through Olive Branch, Illinois 3's southeasterly trajectory catches the southern end of Illinois 127:
Approaching Urbandale and the Cairo area, Illinois 3 meets an interchange with Interstate 57, picking up a southward US Route 51 in the process...
At the intersection of US Route 51 and Illinois 37's southern end near Urbandale, Illinois 3 ends as US Route 51 continues straight ahead into Cairo.