^Northbound trailblazer at US Route 24 in the heart of Eureka, Illinois, January 2021.
Illinois Route 117 runs north-south in central Illinois, in the area east of Peoria but northwest of Bloomington. I don't think it's numbered in reference to Illinois 17, but it spurs off of Illinois 17 to head south through Toluca, Roanoke, and Eureka. Its southern end is at Interstate 74 between Peoria and Bloomington.
The northern end of Illinois 117 is at Illinois 17, just north of Toluca and west of Interstate 39:
The northern end of Illinois 117 is at Illinois 17, just north of Toluca and west of Interstate 39:
Illinois 116 joins from the east near Benson, and Illinois 117 and Illinois 116 go southwest concurrently:
After the concurrency passes through Roanoke, Illinois 117 splits off of Illinois 116 to head south again:
Illinois 117 crosses US Route 24 in Eureka:
Just before ending, Illinois 117 crosses US Route 150 at Goodfield:
Shortly after that, Illinois 117 reaches its southern terminus at Interstate 74...