Interstate 470 in Kansas provides a bypass loop of I-70 and the Polk-Quincy Viaduct through Downtown Topeka. The western half, Dr. Martin Luther King, Jr. Memorial Highway, constitutes a commuter route and part of U.S. 75, a major north-south route across Topeka. The eastern half runs along the tolled Kansas Turnpike between Interchanges 177 and 183.
The 2001-realignment of Interstate 70 at the East Topeka Interchange slightly extended I-470 east to beyond the site of the former Topeka Service Area.
The section of Interstate 470 that overlays the Kansas Turnpike was constructed in 1955 and 1956, with the entire turnpike opening on October 21, 1956. The portions of the Kansas Turnpike that carry I-35, I-70, and I-470 were approved as part of the Interstate Highway System by the Federal Highway Administration (FHWA) in 1957. The remainder of I-470 west of the toll road was constructed in the 1960s.1
A $94-million project started in 1997 redesigned the East Topeka Interchange on the Kansas Turnpike where I-70 and I-470 converge with U.S. 40 and K-4. A new alignment and main line toll plaza for Interstate 70 was constructed, bringing the freeway onto the Turnpike mainline via a high-speed wye interchange at the east end of I-470. This eliminated a trumpet interchange and access road leading north to where I-70 presently meets Rice Road at Exit 365. The work also added access to the Oakland Expressway, the route of K-4 northward across the Kansas River to U.S. 24. The new East Topeka Interchange opened to traffic on August 1, 2001.2