^Illinois 104 heading north away from Business Loop 72 on the west side of Jacksonville, February 2018.
Illinois Route 104 is an east-west route through the western half of central Illinois, in the vicinity of Interstate 72, connecting Quincy to Taylorville via Jacksonville and Auburn. From Jacksonville west, Illinois 104 parallels Interstate 72 to the north; east of Jacksonville, Illinois 104 lies south of that freeway.
The western end of Illinois 104 is right in downtown Quincy, at a point along US Route 24 common to the northern endpoint of Illinois 57...
Farther east in Quincy, by the modern car-oriented shopping malls, Illinois 104 crosses Illinois 96:
As Illinois 104 approaches Jacksonville, it meets the southern end of Illinois 78:
Illinois 104 joins Business Loop 72 eastward through town...
Just south of Jacksonville's downtown, Illinois 104 and Business Loop 72 meet the northern end of Illinois 267:
On the east side of Jacksonville, Illinois 104 splits from Business Loop 72 to head southeasterly under Interstate 72 with no interchange (to access Interstate 72 from Route 104, just follow the Business Loop east for less than two miles)...
Illinois 104 meets the northern end of Illinois 111 at Waverly:
In Auburn, Illinois 104 crosses Illinois 4 (since I took this picture in early 2018, a signal was added to this intersection):