SBI Route 101 was Augusta to US-67 near Littleton, and has not changed since SBI days. It runs in Hancock and Schuyler Counties.

SBI Route 102 was Chatton to Camp Point, mostly on the current IL-94. It changed to IL-94 in 1955.

IL-102 currently runs from Kankakee to Wilmington in Kankakee and Will counties. This road was IL-113 until 1940 when it was changed to IL-113N (An old alignment of US-52, originally also IL-113 became IL-113S then became IL-113 again in 1961.) IL-113S was on the south side of the Kankakee River, and IL-113N was on the north side of the river.

SBI Route 103 was Beardstown to Ripley entirely in Schuyler County. It has not changed since SBI days. There is really no reason this couldn't be changed to IL-125 as an extension of that route, since both end at or near Beardstown.
SBI Route 104 was the current IL-104 from Taylorville to Meredosia, then IL-99 from Meredosia to Mount Sterling. IL-104 now runs west from Meredosia to Quincy in Morgan, Pike, and Adams Countiesover the former IL-105. This was changed to the current designation in 1937.
SBI Route 105 was the current IL-104 from Meredosia to Quincy. This was changed to IL-104 in 1937. In 1945 IL-105 was applied to the old route of IL-47 when IL-47 was relocated north of Decatur. IL-105 now runs from Decatur to I-72 north of Monticello in Macon and Piatt counties.

SBI Route 106 was the current IL-106 from the Mississippi River at East Hannibal to Kinderhook.

  • This became US-36 by the early 1930's and IL-106 was dropped.
  • In 1938 IL-106 was used on a new road from Winchester to Whitehall.
  • In the early 1990's IL-106 was applied to the former US-36 as US-36's new alignment on a freeway west of Springfield took shape. 
  • The section of the old US-36 west of Winchester became IL-106 as US-36 was moved to the new freeway. The freeway is now part of I-72.

IL-106 now runs from East Hannibal to Whitehall thru Pike, Scott and Greene Counties.

SBI Route 107 was from Pike Station to Griggsville.

  • This was changed to US-54 in the early 1930's from Pike Station to Pittsfield, and IL-107 remained on to Griggsville.
  • In 1964 IL-107 was extended to Mount Sterling as an upgrade to an existing road.
  • In 1995 IL-107 was replaced by US-54 from Pittsfield to the new US-36 (later I-72) freeway.

IL-107 currently runs from US-36/I-72 north of Pittsfield to Mount Sterling in Pike and Brown counties.

SBI Route 108 was Kampsville to US-66 (now I-55) north of Litchfield. It still is.... The West end is at IL-100, just west of the Kampsville Ferry landing. IL-108 runs in Calhoun, Greene, Macoupin and Montgomery Counties.
SBI Route 109 was Grafton to near East Newbern on the current IL-3. About 1947, when US-67 was rerouted from Alton to Jerseyville the old US-67 became IL-100 from Alton to near East Newbern and IL-109 north to Jerseyville in Jersey County. In 1987 IL-3 was moved to it's current route.

SBI Route 110 was Jerseyville to Benld. In 1938 it was changed to IL-16 from Jerseyville to Royal Lakes, the current IL-159 (then IL-112) south from there to IL-138, and IL-138 to Benld. Also in 1938, IL-110 was relocated to what is now IL-15 from Nashville to Freeburg. This became US-460 in 1949, and then IL-15 in 1974. It has not been used until July 2010:

IL110 IL110

During the week of August 9, 2010 new markers as shown here appeared on the eastbound and westbound I-88 (Reagen Tolllway) just west of I-355 near Downers Grove, Illinois. They weren't there the week before. These signs bear "IDOT 7-10" marks indicating they were made in July of 2010 in an IDOT sign shop. The ITHA usually handles signage on Illinois' tollways.

There were 2 or 3 markers like this in each direction, although I did not see whether they extended east of I-355.

According to the Quincy Herald-Whig:

Chicago-Kansas City Expressway a reality after six-decade effort
Published: 6/30/2010 | Updated: 7/23/2010
By DOUG WILSON
Herald-Whig Senior Writer

The long-envisioned Chicago-Kansas City Expressway is now officially established as a new national transportation corridor.
A joint resolution approved by the Illinois House and Senate:
* Officially recognizes the corridor.
* Identifies the routes that form the Illinois portion of the C-KC.
* Authorizes a C-KC logo.
* Declares Route 110 to be an additional common designation for the routes that form the corridor.
* Directs that signs with the Route 110 and C-KC logo be installed along the corridor to assist motorists and promote marketing efforts.

(Read the rest at http://www.whig.com/story/news/C-KC-063010)

Closeup of the date mark on the IL-110 sign:

(08-15-2010)

SBI Route 111 was from Waverly to Alton on the current IL-111. In 1942 it was extended south to Fairmont City, and in 1953 to the current end in what was then near East St. Louis, now part of Centreville. From Medora to Alton it was the same as US-67. In 2001 US-67 was changd to IL-267 north of Medora and IL-111 was left by itself south of there. IL-111 currently runs from Waverly to Centreville thru Morgan, Macoupin, Jersey, Madison, and St. Clair counties.
SBI Route 112 was Royal Lakes to Edwardsville. In 1964 it was changed to IL-159 as an extension of IL-159. IL-112 has not been used since.

SBI Route 113 was 2 roads, one on either side of the Kankakee River from Kankakee to Wilmington, as well as the current IL-113 from Diamond west to IL-47. The portion from Diamond east originally ran due east from Diamond to the Kankakee River, and then SE to Custer park and beyond. IL-113 now runs from IL-47 east to Kankakee in Grundy, Will, and Kankakee Counties.

In 1940 IL-113 was changed to IL-113N and IL-113S, with the highway on the North side of the river becoming IL-113N, and the highway on the south side becoming IL-113S. IL-113S was also used on the western end west of the then US-66 (Now IL-53). In 1961 IL-113S was changed to IL-113 and IL-113N was changed to IL-102.

SBI Route 114 was and IL-114 still is from the IN line to Momence, about 12 miles. IL-114 is entirely in Kankakee County.
SBI Route 115 was near Kankakee to Perdueville (near Paxton, at IL-9). The only major change was in 1954 when US-45 was moved to a new road IL-115 was extended north a few miles on the old road. IL-115 now runs from Kankakee to Perdueville in Kankakee and Ford Counties.

SBI Route 116 was from IL-49 east of Ashkum to East Peoria.

  • In 1937 IL-116 replaced US-124 from East Peoria to US-24 near Biggsville.
  • In 1969 US-45 was relocated due to the construction of I-57, and IL-116 was replaced by US-45 east of Ashkum.

IL-116 now runs from Ashkum to near Biggsville in Iroquois, Ford, Livingston, Woodford, Peoria, Fulton, Knox, Warren, and Henderson Counties.

There was once at least one "Spur-IL-116" that ran from IL-116 to Raritan.

IL-116A was on the current IL-117 from IL-17 to IL-116 thru Toluca. This was changed in 1994, and it was the last surviving "Letter" route in IL.
SBI Route 117 was US-150 to IL-116 thru Eureka. In 1994 IL-117 was extended to IL-17 thru Toluca, and partially as a second number on IL-116 thru Roanoke to replace the last surviving "Letter" route, IL-116A. IL-117 currently runs from near Toluca to I-74, in Marshall and Woodford Counties.
SBI Route 118 was Streator to Pontiac. In 1933 this was changed to IL-23. From 1935 to 1938 IL-118 was used on St. Charles Road in the Chicago area. IL-118 has not been used since 1938.
SBI Route 119 was Heyworth to the Indiana Line north of Danville. In 1937 IL-119 was extended west to Havana, and replaced IL-119A and IL-122. In 1951 IL-119 west of IL-1 was changed to US-136. The only part still existing in IL is from IL-1 to the IN line, about 6 miles, all in Vermilion County.
IL-119A was originally a short spur to Armington, and the current US-136 from here to the old US-66. All except the spur was changed to IL-119 in 1937. The spur was un-numbered until around 2005 when a couple "Spur 136-A" signs appeared between Armington and US-136.
SBI Route 120 was Havana to Mason City, and became US-119 in 1937. This then became US-136 in 1951. In 1941 IL-120 replaced IL-20 from Waukegan to Woodstock, since this road was close to US-20. As part of the Great Purge, IL-120 was removed east of Green Bay Road (IL-131) in 1972.

Route overview and markers

Updated 08-15-2010