605 ILCS 5/5-301
In order to properly plan the utilization of motor fuel tax funds each County Superintendent of Highways, except for those in a county with a population of 185,000 or less, shall be required to develop and update a 20 year long-range highway transportation plan. The plan shall contain an estimate of revenues which will become available during that period and a statement of intention with respect to the construction, maintenance, and other related work to be done insofar as it is possible to make such estimates. In addition, the long-range plan shall show the location of existing county highways and the general corridors of future highways, the projected future traffic usage on each highway for a 20 year period, a tabulation showing the design standards and the geometric features associated with different levels of traffic usage, and a listing of the major improvements anticipated within 5 years of the date of each plan. A copy of the plan shall be filed with the Secretary of the Department of Transportation. A copy of the plan as it relates to each city over 5,000 population in the county shall be filed with the clerk of each municipality. The initial plan shall be on file with designated agencies by July 1, 1971, and shall be updated on an annual basis thereafter.
605 ILCS 5/5-301