Oklahoma State Highway 14 route continued north along present-day U.S. 281 through Alva to the state line south of Hardtner, Kansas. (The old road north of Vici became part of SH-34.) New U.S. routes were added to Oklahoma's highway system in 1938. Among these were US-281, formerly a split route with one section in Kansas and one in Texas, which was connected in 1938 via Oklahoma; also added in 1938 was a southern extension of US-183. These two routes were overlaid onto SH-14, with US-183 entering the state from the south near Davidson and following the SH-14 route to Seiling, and US-281 taking the
Kansas Turnpike turnpike proceeds due north from the state line, with no interchanges for its first in Kansas. The southernmost interchange on the turnpike is Exit 4 (South Haven), which serves US-166. US-166 heads east to Arkansas City and west to US-81 at South Haven. This interchange is a four-ramp folded diamond with ramps in the southeast and northwest quadrants. It has no toll plazas, as it lies south of the southern barrier toll. Northbound traffic must exit at US-166 to avoid paying a toll. Initially, the interchange provided only a southbound exit and northbound entrance, forcing drivers who did not wish