SBI Route 141 was Norris City to New Haven in White County.
It currently runs US-45 near Gossett to the Wabash River bridge in White County.
SBI Route 142 was Effingham to McLeansboro over the current IL-37 to Mt. Vernon and IL-142 Mt. Vernon to McLeansboro.
IL-142 runs from Mt Vernon to Equality in Jefferson, Hamilton, Saline, and Gallatin Counties.
|SBI Route 142A was: IL-142A, from 1926 to 1942; IL-147, 1942 to 1947; IL-142, 1947 to 1974; and IL-242, 1974 to present. IL-142A has not been used since 1942.|
|SBI Route 143 was Benton to Harrisburg. In 1937 this IL-143 was replaced by IL-34 when IL-34 was extended north. Also in 1937, IL-143 was used to replace IL-127A east from Highland to IL-127. In 1950 IL-143 was extended west to Edwardsville. In 1964 IL-143 was extended further west to Alton replacing IL-159 west of Edwardsville. IL-143 now runs from Alton to near Beavercreek in Madison and Bond counties.|
|SBI Route 144 was from Grimsby to Murphysboro. This was changed to IL-149 in 1964. It has not been used since.|
|SBI Route 145 was Metropolis to Dixon Springs. In 1955 it was extended to Harrisburg on a new road except for the last 5 miles which was a second number on IL-34. IL-145 now runs Metropolis to Harrisburg thru Massac, Pope, and Saline counties|
|SBI Route 146 was East Cape Girardeau to Golconda. In 1937 it was extended to Elizabethtown, replacing the eastern leg of IL-34. In 1942 it was extended further east to north of Cave in Rock on a new highway. Its current run is from East Cape Girardeau to Cave in Rock in Alexander, Union, Johnson, Pope, and Hardin counties.|
|SBI Route 147 was Marion to Cairo, now part of IL-37. From 1942 to 1947 it was used on the former IL-142A from McLeansboro to Wayne City. This was changed to IL-142 in 1947, and IL-242 in 1974. In 1947 IL-147 was used on a road from Vienna to Glendale where it exists today. This is in Johnson and Pope Counties.|
|SBI Route 148 was Marion to Mt. Vernon. In 1964 it was extended south a few miles to Pulleys Mill on a new road. It now runs Mt. Vernon to Pulleys Mill in Jefferson, Franklin, and Williamson Counties.|
|SBI Route 149 was Thompsonville to Hurst. In 1963 it was extended west to past Murphysboro, replacing IL-144. It now runs Thompsonville to IL-3 in Franklin, Williamson, and Jackson Counties.|
|SBI Route 150 was Cairo to Hamel, including the US-60/62/51 bridges over the Mississippi and Ohio Rivers at Cairo. In 1937 the portion of IL-150 from Cairo to Chester was changed to IL-3 as an extension to IL-3, and the section north of Steeleville was changed to IL-43. IL-150 then was extended to north of Cutler on the former IL-151. IL-150 now runs from Chester to near Cutler in Randolph and Perry Counties.|
US-150 runs from Terre Haute IN thru IL to Moline. It parallels I-74 for all but the portion south of Danville, where it is collocated with IL-1 to Paris. US-150 first appeared on IL maps in 1936, prior to that the route was as follows:
There is no real reason why this route should still exist in IL, but it does. There is no reason other than the cost of the work that it couldn't be removed from the entire route west of Terre Haute. Some sections could be renumbered to State route numbers as extensions to current routes. A couple of suggestions include using IL-16 from Paris east, IL-10 from Danville to Champaign, IL0164 from Galesburg to Champaign and IL-41 north of Galesburg.
|Business US-150 was used during the 1960's on the original route of US-150 in the Champaign-Urbana area when US-150 was relocated to the then new I-74. It returned to US-150 after a few years.|
|SBI Route 151 was near Steeleville to Murphysboro. This route was changed to IL-43 in 1937, and IL-4 in 1964. In 1940 IL-151 was applied on a new road from Ava to IL-3 in Jackson County.|
|US-151 ran on the current IL-35 from the WI line thru East Dubuque to the US-20 bridge thence into Iowa with US-20 from 1971 to 1982 after the old Eagle Point bridge was abandoned until the new bridge was complete. US-61 was also here at the time. After the new bridge was completed in 1982, US-151 (and US-61) was rerouted back to its old WI-IA alignment.|
|SBI Route 152 was (and IL-152 still is) a 7 mile long road that heads west from DuQuoin to IL-127, entirely in Perry County. It has not changed since SBI days.|
|SBI Route 153 was Eden to Irvington on the following current routes: IL-153, Eden to IL-15 IL-15, IL-153 to Nashville IL-127, Nashville to New Minden, IL-177, New Minden to Irvington. In 1937 IL-153 was drawn back to near Plum Hill, and the above numbers were applied to the former IL-153. In 1938 it was drawn back further to its current northern end at IL-15. In 1939 it was extended south to Sparta from Eden. IL-153 currently runs Eden to IL-15 in Randolph and Washington Counties.|
|SBI Route 154 was Pinkneyville to US-51, near Sunfield. In 1937 it was extended west to Red Bud, replacing IL-170 (Red Bud to Sparta) and (IL-13 Pinkneyville to Sparta) due to the relocation of IL-13. In 1984 IL-154 replaced IL-183 from Sesser to Whittington over the manmade Rend Lake (built in 1970 by damming creeks). The section between US-51 and Sesser was a new road. The current IL-154 runs Red Bud to Whittington in Randolph, Perry, and Franklin Counties.|
|SBI Route 155 was (and IL-155 still is) Ruma to a point 4 miles west of Prairie du Rocher entirely in Randolph County.|
|I-155 runs from I-55 at Lincoln north to I-74 at Morton (about 31 miles) to allow access to Peoria from Springfield. This is an upgrade to the old IL-121. This was originally proposed to be I-37, but this application was declined by AASHTO and a 3DI was suggested instead.|
|SBI Route 156 was (and IL-156 still is) New Athens to Harrisonville in St. Clair and Monroe Counties.|
|SBI Route 157 was Cahokia to Glen Carbon, on the current IL-157. IL-157 was extended in 1946 south to the Jefferson Barracks Bridge to Missouri via the current IL-3 and US-50/I-255. This was pulled back to Cahokia in 1958. In 1965 the north end was extended to Hamel replacing Bypass US-66 (this route had been US-66 prior to 1957) IL-157 now runs Hamel to Cahokia in Madison and St. Clair Counties.|
|SBI Route 158 was Columbia to Belleville on the current IL-158. In 1946 it was extended north to O'Fallon and the east end was extended to the Jefferson Barracks Bridge. In 1959 it replaced IL-157 on the bridge approach. In 1960 it was drawn back to the old end at the east end of Columbia. It currently runs Columbia to O'Fallon in Monroe and St. Clair Counties.|
|SBI Route 159 was Alton to Red Bud. In 1964 Alton to Edwardsville was changed to IL-143, and IL-159 was extended north from Edwardsville to Royal Lakes, replacing IL-112. In 2003 IL-2003 was rerouted thru Edwardsville. In 2007 IL-159 was rerouted along Illini Street and Main Street in Edwardsville. IL-159 now runs Red Bud to Royalton in Randolph, Monroe, St. Clair, Madison, and Macoupin Counties.|
|Alternate IL-159 was proposed by Edwardsville to replace IL-159 on the old route thru town but after the reroute occurred the old route was left un-numbered.|
|SBI Route 160 was Alton to Greenville. This was changed to IL-140 in 1935. In 1959 it was applied to a road from Highland to New Baden. In 1960 it was extended south to New Memphis. In 1965 it was extended north to IL-140. In 1967 it was extended east from New Memphis to the current IL-15 when IL-15 was relocated. A portion of this route is also IL-177.|