Kansas numbered highways

Interstate 135 (abbreviated I-135) is a 95.7-mile-long Interstate Highway in central and south-central Kansas, USA. I-135 runs between the cities of Salina and Wichita. The interstate's northern terminus is at the junction of Interstate 70 and its southern terminus is with Interstate 35 (the Kansas Turnpike).

Until 1976, I-135 was designated as I-35W. It is the longest "spur" (3-digit number, first digit odd) in the Interstate system.

I-135 begins from the south at Exit 42 on the Kansas Turnpike. (The exit is signed as I-135, I-235, US-81/Wichita/Salina.) US-81 joins I-135 half a mile later, and remains concurrent with it for the rest of its length. Less than a mile from the Kansas Turnpike tollbooth, I-235, a loop around the western side of Wichita, branches off the highway. I-135 continues northward from there, running just east of the Wichita downtown area. It reunites with I-235 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 miles (32 km), returning to a due north course at McPherson. The route ends north of Salina, at its intersection at I-70.

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