In 1948 or 1949, NC 18 was rerouted onto new bypass south of downtown Lenoir; its old alignment along Harper Avenue became NC 18A. In 1952, NC 18 was placed on new routing between Laurel Hill and Morganton with a 3 miles routing through Catawba County; the old routing through Camp Creek and Sunnyside was downgraded to secondary road "Old North Carolina Highway 18" (SR 1100 Gaston County, SR 1555 Cleveland County and SR 1924 Burke County).