Interstate 135

Interstate 135 (I-135) is an approximately 95.7 mi auxiliary Interstate Highway in central and south-central Kansas, United States. I-135, which is signed as north–south, runs between I-35 and the Kansas Turnpike in Wichita north to I-70, U.S. Highway 40 (US-40), and US-81 in Salina. Except for the first 0.46 mi, I-135 overlaps US-81 its entire length. The route also runs through the cities of McPherson, Newton, and Park City.

The highway was designated as Interstate 35W (I-35W) until September 1976, when it was renumbered as I-135 to conform to new AASHTO policies that eliminated most suffixed Interstate Highways. It is currently the longest three-digit "spur", with an odd first digit, in the Interstate System.

Route description
I-135 begins from the south at exit 42 on the Kansas Turnpike. (The exit is signed as I-135/I-235/US-81 for Wichita and Salina.) US-81 joins I-135 0.5 mi later at exit 1A (East 47th Street South) and remains concurrent with it for the rest of its length. Less than 1 mi from the Kansas Turnpike tollbooth, I-235, a loop around the westside of Wichita, branches off the highway at exit 1C. I-135 continues northward from there, running just east of the Wichita downtown area. It reunites with I-235 at exits 11A and 11B at milepost 11 at the loop's other end.

I-135 leaves Wichita and continues northward to Newton where it turns northwest around milemarker 33. The freeway continues in this direction for 20 mi, returning to a due north course at McPherson.

The stretch of I-135 in Saline County from the Saline–McPherson county line to the highway's terminus at I-70, is designated as the Ben E. Vidricksen Highway, in honor of a state senator who was active in pushing for the highway's enlargement.

The route ends on the northwest side of Salina, at its intersection at I-70. The road continues as US-81 north of this interchange.

History
Construction on the Canal Route portion of I-135 (in Wichita, where the Chisholm Creek Canal runs through the median of the highway) was begun in 1971. This portion of the route took eight years to complete with a cost of $32 million (equivalent to $ in ). It was built through the middle of the city's African-American neighborhood, known as McAdams.

Until September 13, 1976, I-135 was signed as Interstate 35W (I-35W). The Interstate's full length was completed in December 1979.

In 2021, work began to rebuild the northern junction with I-235 in Wichita. A two-lane flyover ramp connecting northbound I-135 to southbound I-235 which replaced the previous one-lane loop ramp opened on May 31, 2023.