Interstate 335 follows the Kansas Turnpike between I-35 at Emporia and I-470 at Topeka. A lone service plaza and interchange (Exit 147) with U.S. 56 near the city of Admire line the 50.17 mile long rural stretch. 2018 traffic counts ranged from 9,150 vehicles per day (vpd) north from Emporia to 9,500 vpd south of Topeka.
A number of overpasses along the I-335 section of the Kansas Turnpike do not meet Interstate height standards. Therefore over height trucks are directed off the turnpike northbound at Emporia or southbound at the South Topeka interchange.
The Kansas Turnpike was constructed in 1955 and 1956, with the entire toll road opening on October 21, 1956. The portions of the Kansas Turnpike that carry I-35, I-70, and I-470 were approved by the Federal Highway Administration (FHWA) for inclusion in the Interstate Highway System in 1957.1 The turnpike is signed as I-35 from the Oklahoma State line north to Emporia (Exit 127); I-335 from Emporia northeast to I-470 (Exit 177); I-470 from Exit 177 to I-70 (Exit 182); and I-70 from Exit 182 east to U.S. 24-40-73/K-7 (Exit 224) at Bonner Springs. The turnpike system utilizes one exit number system regardless of the route number.
Also as approved by the FHWA, Interstate 335 was designated on the unnumbered section of the Kansas Turnpike on October 23, 1987. Kansas sought Interstate status for this stretch of the turnpike as part of the law passed by Congress that raised the speed limit from 55 to 65 miles per hour on rural Interstate routes (those outside urban areas with populations exceeding 50,000). Inclusion of the unnumbered section of the Turnpike into the Interstate system qualified the route for the higher speed limit.2
Changes were made to the south end of Interstate 335, where I-35 overtakes the Kansas Turnpike southwest from Emporia to El Dorado. A $32.9 million project both reconfigured a directional interchange with left side ramps joining I-35 with adjacent U.S. 50, and relocated the trumpet interchange with the freeway and toll road. Previously I-35 utilized a TOTSO (turn off to stay on) connection from the Emporia bypass to the Kansas Turnpike toll plaza. Replacing the previous ramp configuration dubbed by the Kansas Department of Transportation (KDOT) as the “spaghetti bowl,” the freeway was realigned to meet Interstate 335 directly with a new diamond interchange and roundabout system. Work on the new exchange was completed in November 2008.3