In 1940, DSHD initiated traffic surveys and studies to inform plans to construct a four-lane divided highway south from Dover. The studies, completed in 1942, found that US 13 from Delmar to Dover carried significantly more traffic than US 113 from Selbyville to Dover, so DSHD started planning for the divided highway to the Maryland state line to be along the US 13 corridor. However, DSHD also approved plans for expansion of US 113 to a divided highway from Milford to Little Heaven. DSHD completed the final link in the Dover–Delmar divided highway in 1957. As in Delaware, Maryland SRC prioritized completing expansion of US 13 to a four-lane highway from Virginia to Delaware, which was completed in 1966. By that time, only a small portion of US 113 around Berlin had been expanded to a divided highway.