The Kansas Turnpike was built from 1954 to 1956, predating the Interstate Highway System. While not part of the system's early plans, the turnpike was eventually incorporated into the Interstate system in late 1956, and is designated today as four different Interstate Highway routes: I-35, I-335, I-470, and I-70. The turnpike also carries a piece of U.S. Routes 24 and 40 in Kansas City.