US 23 crosses the Ohio River from Kentucky and enters Portsmouth and passes through the towns of Lucasville, Piketon, Waverly, Chillicothe, and Circleville, before reaching Columbus. The highway then mostly follows High Street in Columbus, which was the original route. However, it now bypasses the central business district and northern Columbus neighborhoods by following the one-way pairing of 4th Street (northbound) and 3rd/Summit Street (southbound) between the downtown area and Hudson Street, and Indianola Avenue north before returning to its original course on High Street at Morse Road. US 23 then follows High Street northbound from Columbus, going through Worthington, passing the village of Lewis Center, entering Delaware at the Cheshire Road intersection. After US 23 intersects the northern terminus of SR 315 and passes a retail district, it becomes a limited-access freeway, bypassing downtown Delaware, before resuming as an expressway with at-grade crossings north of the city.