Interstate 39 runs through the backbone of north-central Illinois, starting at Bloomington-Normal and heading north to Rockford and beyond. It spends about 140 miles within the state of Illinois before crossing into south-central Wisconsin. It is concurrent with US Route 51 for its entire length in Illinois (save for about 1000 feet right before the Wisconsin border).
Exit 2 is the northern end of US Route 51's Business Route that heads south through Bloomington-Normal...
Exit 5 is a diamond interchange providing access to the town of Hudson and McLean County Highway 12...
Exit 8 provides access to the southern end of Illinois 251, as well as McLean County Highway 8 and the town of Kappa...
Exit 14 is a fountain interchange to US Route 24, alongside the town of El Paso, and Peoria is also mentioned on the sign...
Exit 22 is a diamond interchange to Illinois 116, which connects to Peoria and Pontiac...
Exit 27 accesses Minonk, as well as Woodford County Highway 2...
Exit 35 is for Illinois 17, which connects with Wenona and Lacon:
Exit 41 is for Illinois 18, which can be used to reach Henry and Streator:
Exit 48 provides access to Tonica, and LaSalle County Highway 54, which extends east, becoming LaSalle County 14 and taking travelers to the southern end of Illinois 178:
Exit 51 reaches Illinois 71 with access to Oglesby and Hennepin:
Exit 52 is for Illinois 251 which crosses from southeast to northwest, and "LaSalle-Peru" is labeled as the pair of control cities:
Exit 54 is a diamond interchange with access to Oglesby via LaSalle County Highway 23:
Exit 57 provides access to US Route 6, LaSalle-Peru, and Ottawa:
Exit 59A is the first half of the cloverleaf interchange with Interstate 80; this first ramp accesses Interstate 80 east toward Chicago:
Exit 59B is the cloverleaf ramp to Interstate 80 westward, toward Des Moines:
Exit 66 is for US Route 52, with access to the town of Troy Grove:
Exit 72 accesses US Route 34, connecting to Earlville and Mendota:
Exit 82 is a diamond interchange providing access to Paw Paw:
Exit 87 reaches US Route 30, with Sterling-Rock Falls and Aurora listed as control cities:
Exit 93 is a fountain interchange accessing Steward:
Exit 97A, near Rochelle, is the first half of a cloverleaf interchange to Interstate 88; this first ramp connects to Interstate 88 eastward toward Chicago:
Exit 97B is the latter ramp accessing Interstate 88 west, toward Moline-Rock Island:
Exit 99 reaches out to Illinois 38, with access to Rochelle and DeKalb:
Exit 104 is for Illinois 64, with access to Oregon and Sycamore:
Exit 111 is for Illinois 72, and though Monroe Center is right next to the interchange, Byron and Genoa are the only control cities listed on signs:
Exit 115 is for Baxter Road, on the southern outskirts of the Rockford area:
On the southern flank of Rockford, Interstate 39 and US Route 51 both join the US Route 20 bypass freeway eastward; though no exit number is shown, the exit number is probably "119":
Exit 122A is the first half of a cloverleaf interchange with Harrison Avenue, and at this first exit, US Route 20 splits away to continue east toward Belvidere:
Exit 122B, at the second ramp of the cloverleaf, puts drivers on Harrison Avenue westward into Rockford:
At another unmarked exit (we'll call it "123"), Interstate 39 can access Interstate 90 east, but Interstate 90 joins Interstate 39 north here:
Interstate 39 now has joined Interstate 90 north, and the concurrent highway uses Interstate 90's exit numbers. Exit 15, in the Rockford area, accesses Business US Route 20, also known as State Street:
Interstate 90's exit 12 allows Interstate 39 to access Riverside Blvd in the Rockford area:
Still in the Rockford area, Interstate 90's exit 8 allows Interstate 39 to reach Illinois 173, labeled as "West Lane Road":
Interstate 90's exit 3 allows Interstate 39 to access Rockton Road (Winnebago County Highway 9):