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.

It is currently the longest three-digit "spur", with an odd first digit, in the Interstate System.

US-81 joins I-135 0.5 miles (0.80 km) later at exit 1A (East 47th Street South) and remains concurrent with it for the rest of its length.

Less than one mile (1.6 km) from the Kansas Turnpike tollbooth, I-235, a loop around the westside of Wichita, branches off the highway at exit 1C.

The freeway continues in this direction for 20 miles (32 km), returning to a due north course at McPherson.