The DuPont Highway was a boon to southern Delaware, which had formerly been economically isolated from the large cities of the northeast. In conjunction with the rise of the automobile, the highway spurred the growth of the Delaware Beaches by greatly improving access to the coast for tourists from northern Delaware and adjacent portions of the Northeast megalopolis. Southern Delaware also developed into a major truck farming region due to having much greater access to urban markets. No longer fully reliant on the railroads to transport their goods, farmers in Sussex and Kent counties could market their fruits, vegetables, and broiler chickens directly to consumers in the north. However, the passenger and freight traffic induced by this increased economic integration and the automobile boom of the 1920s meant that these roads in Delaware and Maryland constructed in the 1910s and 1920s, which were built with widths of , were no longer adequate for the traffic they served. In particular, by 1929 the Selbyville–Milford portion of the DuPont Highway was the only through highway in Delaware with a width of less than . The highway's importance was further implied when the Pocomoke City to Dover highway became part of the United States Numbered Highway System. The Pocomoke City–Dover route was designated Route No. 113 in the preliminary system proposed in November 1925, and that number and course were confirmed in the system AASHO and the Bureau of Public Roads approved in November 1926. The U.S. Highway's original southern terminus was the intersection of Market Street and Sixth Street in Pocomoke City. US 113's northern terminus was the split between the two main north–south highways of southern Delaware at Coopers Corner north of Puncheon Run on the southern edge of Dover.