 In 1969 the route was extended southwestward from US 30 to its current terminus, replacing part of Iowa 64 (this section was originally Iowa 88).In 1989, it was re-routed to bypass Marshalltown, replacing Iowa Highway 233, a spur route from Iowa 14 to Albion.In 2002, the between US 65 and US 30 were upgraded to expressway status.