The Last of the Suffixed Illinois Highways: Illinois Route 116A
The last suffixed Illinois State Highway, Route 116A, lasted a lot longer than you might think, as it wasn't replaced until 1993.
|Image and article: Woodford County Journal, 1/21/93. I wonder where that "Formerly 116A" sign is now...
Illinois Route 116 originally ran from East Peoria to Ashkum on an alignment similar to how it does today, with two exceptions; it was replaced in favor of US-45 slightly east of Ashkum when I-57 was constructed, and the most notable change was it was extended west to IL-94 to completely replace US Highway 124.
At Benson, IL-116 made a pretty abrupt turn south, and a spur went north to Toluca and IL-17, this was known as IL-116A.
|1930 Illinois State Highway Map
While many suffixed highways existed in Illinois' State Highway system, they were either replaced by extensions of existing routes (as is the case with 116A), given new numbers freed up from deletion (which is how IL-59A became IL-60, for example), or simply became unmarked state highways, which are plentiful in the state.
I can't think of another example of a suffixed route that survived beyond 1970, and many were deleted much earlier, so why it took so long to remove 116A is beyond me.
|Google Maps. IL-116 through Benson, heading south, it becomes IL-116/117. To head north, one would use IL-117, the former IL-116A.
IL-117 originally ended at 116 west of Roanoke, but was extended and multiplexed with 116 through the Benson junction to head north and eliminate 116A.
While I personally like suffixed routes, I can understand why IDOT prohibits them, since they can be confusing, and frankly the 117 number works perfectly in this situation, as its north end is at IL-17.
Depending on whom you ask, there may be another suffixed route in Illinois, but this one is a little weird. There is a spur off of US-136 that would reasonably be numbered Spur-136 with a US Highway shield, but for some reason is signed as SPUR-136A.
|SPUR-136A sign put up by IDOT in 1999. Bill Burmaster photo. Once again, I have to ask, what were they thinking?