Kansas numbered highways

Interstate 470 (I-470) is a 13.72-mile (22.08 km) loop highway that bypasses the downtown area of Topeka, Kansas . I-470 begins at I-70 in western Topeka and heads southeast, running concurrent with U.S. Route 75 (US 75). At the I-470 junction with I-335, the freeway becomes part of the Kansas Turnpike until I-470 reaches its eastern terminus with I-70. The Kansas Turnpike was opened in the 1950s, comprising the eastern portion of the route. Several years later, in the early 1960s, the western section of I-470 was opened to traffic.

Interstate 470 begins in the northwestern part of Topeka at an interchange with I-70, US-40, and K-4. US-75 approaches the interchange from the east and joins I-470. The two routes head southeastward along the western edge of the city. Along this stretch of the interstate, there are three interchanges; exits 1B, 2, and 3. Because of both the southeast-to-northwest alignment of the road and the proximity of two cross-streets, exits 1B and 3 are each made up of two half-diamond interchanges. At exit 1B, traffic leaving eastbound I-470 is deposited onto Huntoon Street. Vehicles merging onto eastbound I-470 must access the entrance ramp from Wanamaker Road. The intersection of Huntoon and Wanamaker is adjacent to the freeway. Exit 3 is constructed similarly to exit 1B, while exit 2 is a standard diamond interchange.

Through southern Topeka, I-470 / US-75 curve to the east-southeast where they intersect Gage Boulevard. Further southeast, US-75 splits away from I-470 at a complex interchange with Burlingame Road. Just east of the US-75 interchange, a trumpet interchange provides access to Topeka Boulevard. The highway then passes through a toll plaza and merges with the Kansas Turnpike, making I-470 into a toll road. This junction also marks the northern end of I-335. I-470 and the Kansas Turnpike head northeast towards I-70. The tollway continues northeastward through southeastern Topeka, passing near to Lake Shawnee and eventually reaching I-470's terminus at I-70, which the turnpike carries east.

The freeway is maintained by the Kansas Department of Transportation (KDOT), who is responsible for maintaining and constructing highways in Kansas. As part of this role, KDOT surveys traffic on their highways in terms of average annual daily traffic (AADT), which is a measure of traffic volume for any average day of the year. In 2007, KDOT calculated that as few as 10,370 vehicles used I-470 daily along the Kansas Turnpike near the I-70 interchange and as many as 43,000 vehicles used I-470 daily west of the Gage Boulevard interchange. As part of the Interstate Highway System, the entire route is listed on the National Highway System, a system of roads that are important to the nation's economy, defense, and mobility.

The section of I-470 that now runs along the Kansas Turnpike was opened in 1956, and was the first part of I-470 to be built. After the founding of the Interstate Highway System that same year, several Interstate freeways were planned through Topeka, including I-70, I-335, and I-470. Construction began on I-470 after I-70's completion through Topeka. The segment of the I-470 freeway from the I-70 interchange to the Kansas Turnpike, most of which is concurrent with US 75 was still under construction in 1960. The next year, in 1961, the unfinished section of I-470 was opened to traffic. Since completion of the freeway, the route has not been changed. It retains its original routing.

Exit 182 is a part of the Kansas Turnpike and use its mileposts, as do all other Interstates signed on the turnpike. The entire route is in Topeka, Shawnee County.