<Li> Route B in Cole County is a four - lane divided highway from US 54 to Lorenzo Greene Dr in Jefferson City, and is an upgraded two - lane highway with shoulders for the rest of the way south to Wardsville . Both sections have a 60 mph speed limit . </Li> <Li> Route C in Cole County is an upgraded two - lane highway with shoulders, and has a 60 mph speed limit from just west of Jefferson City to just east of Russellville . </Li> <Li> Route A in Osage County follows the former routing of US Route 50 from its intersection with modern - day US 50 to Loose Creek . Since the roadway is designed to the same standards as a major highway, the speed limit is 60 on that stretch of road . </Li> <P> In the urban areas of: St. Louis, Kansas City, Columbia, St. Joseph, and Springfield, the speed limit typically drops to 60 mph on Interstates and freeways . In addition, on I - 44 in Rolla the speed limit is reduced to 60 mph from just west of Exit 184 to Exit 186 because of a substandard design . </P>

When did illinois change speed limit to 70