US-400 and US-54 start going together at Mullinville. This goes through Greensburg, Pratt and Kingman before going into Wichita. While in Wichita, US-400 and US-54 intersect Interstate 235. It goes along with US-81 and Interstate 135. K-96 provides a short freeway connection to Interstate 35, which is also the Kansas Turnpike. At Augusta, US-400 and US-54 goes along with US-77. US-400 separates at Haverhill.