It then continues traveling north through Derby, finally joining I-135 and US-81 in Wichita.

K-15 is a multilane divided highway beginning immediately southeast of Mulvane at its intersection with K-53.

It overlaps US-56 east for 6 miles (9.7 km) then continues north through Durham before crossing K-4.

K-15 overlaps K-18 another 4 miles (6.4 km) before returning north and crossing US-24 at Clay Center.

K-15 overlaps US-36 for 6 miles (9.7 km) before returning north to end at the Nebraska border, becoming N-15.

[9] The entire 1.910 miles (3.074 km) section within Clay Center is maintained by the city.