Construction shifted to the south side of Williamsport in the mid-1960s. MD 68, which had been extended west to Clear Spring in 1956, was relocated south of Williamsport, replacing Sunset Avenue and what is now Kendle Road, in 1965. MD 68 was relocated for a grade separation of the Cumberland Valley Railroad and to tie into an interchange with I-81 and the south end of Conococheague Street. MD 63's route north into Williamsport, Artizan Street, was cut off by the construction of I-81, so the state highway joined MD 68 in a concurrency north to US 11. The new alignment of MD 63 and MD 68 was built as a four-lane divided highway around the interchange with I-81, which originally only contained ramps to and from the direction of West Virginia when the interchange opened with the completion of I-81 in 1966. That interchange was completed with ramps to and from Hagerstown between 1981 and 1989.