Construction, first at the U.S. 31/State Road 38 interchange, is to begin in 2011, said the Indiana Department of Transportation. INDOT hasn't yet announced a timetable for other sections.
The Federal Highway Administration signed off on the environmental impact statement Dec. 1.
The state is upgrading U.S. 31 to interstate standards, which will include new interchanges.
The project could displace 63 homes, 33 businesses, 13 office buildings, two churches and two schools, according to the environmental impact statement.
Also affected are 31 acres of forested land.
The document is available at most public libraries in Hamilton County and at www.us31hamiltoncounty.in.gov.