The first section of US 113 to be expanded to a divided highway was part of the new US 13 bypass of Dover. The latter highway's new four-lane course, which included a new bridge across the St. Jones River, was constructed starting in 1950 and opened to traffic April 16, 1952. As part of the project, the portion of US 113 from State Street north of Silver Lake to the new US 13 highway was expanded to a divided highway, and both U.S. Highways were marked on the expanded highway from State Street to their split at the modern intersection of US 13 and Bay Road. DSHD may have removed US 113 markers from north of Bay Road as early as 1965, and the American Association of State Highway and Transportation Officials (AASHTO) approved the northern terminus of the U.S. Highway being retracted from the north end of State Street to where US 13 meets Bay Road at their spring 1974 meeting. In conjunction, AASHTO approved removing US 113 Alternate from State Street north of US 13 and instead following US 13 to US 113's northern terminus.