^Westbound trailblazer leaving Illinois 127 and Hillsboro, February 2023.
Illinois Route 16 runs east-west, almost spanning the entire width of the state, along the southern extent of what I'd call "central Illinois" (just as Illinois 17 runs across the northern extent of "central Illinois"). It runs from Hardin, at the southernmost Illinois River bridge, east through various rural towns, large and small, before ending in Paris. It may not exactly span the entire width of the state, but it runs from a county bordering Missouri to a county bordering Indiana, passing through places such as Jerseyville, Hillsboro, Shelbyville, Mattoon, and Charleston.
The eastern end of Illinois 16 is also the eastern end of Illinois 133, at US Route 150 and Illinois 1 in Paris:
The eastern end of Illinois 16 is also the eastern end of Illinois 133, at US Route 150 and Illinois 1 in Paris:
Illinois 16 and Illinois 133 both run westerly from their shared eastern terminus, but they split up on the west side of Paris:
Illinois 16 has more of a west-southwesterly angle, and at the town of Kansas, Illinois 49 joins it from the north:
West of Kansas, Illinois 49 splits from Illinois 16 to resume going south:
In Charleston, Illinois 16 crosses Illinois 130:
As Illinois 16 enters Mattoon going westward, it meets a full cloverleaf interchange with Interstate 57:
In Mattoon, Illinois 16 is joined by US Route 45 and Illinois 121, which come from the south:
Illinois 16's triplicate concurrency only lasts one block, though, and US Route 45 and Illinois 121 turn toward the north:
At Windsor, Illinois 16 joins Illinois 32 south:
Illinois 32 splits from Illinois 16 soon after:
In Shelbyville, Illinois 16 is joined by Illinois 128, which comes from the north:
The two routes continue west for three miles, then Illinois 128 splits from Illinois 16 to head south again:
Before reaching Pana, US Route 51 joins from the north to follow Illinois 16 west:
In Pana, the concurrency of Illinois 16 and US Route 51 meet the southeastern end of Illinois 29:
In central Pana, Illinois 16 and US Route 51 split up:
After diving southwestward through several coal-mining towns, Illinois 16 joins Illinois 127 north and west through Hillsboro...
After exiting Hillsboro, Illinois 16 and Illinois 127 split to go their separate ways...
In Litchfield, Illinois 16 meets an interchange with Interstate 55...
In the town of Gillespie, Illinois 4 comes from the north to join Illinois 16 west:
The duplex only lasts several blocks, and soon Illinois 4 is departing Illinois 16 to continue south:
At Royal Lakes, Illinois 16 meets the northern end of Illinois 159...
At Jerseyville, Illinois 16 crosses US Route 67, just north of the end of Illinois 109:
Illinois 16 joins Illinois 100 northwest for its final four miles...
Finally, Illinois 16 crosses the southernmost bridge over the Illinois River, concurrent with Illinois 100, to end in Hardin at the first junction encountered after the bridge crossing.
