The year after US 113 Alternate was assigned, State Street through Dover was reconstructed and widened and construction began on a new bridge for US 13 and US 113 Alternate across Silver Lake. The hazardous, narrow causeway was replaced with a four-lane, brick-lined, reinforced concrete triple-arch bridge, and State Street between the bridge and the beginning of the US 13 divided highway at US 113's northern terminus was widened to four lanes, in 1937. The intersection of US 113 and US 113 Alternate at Little Heaven was reconstructed as a directional intersection in 1956. After US 13's bypass of Dover was completed in 1952, the northern termini of US 113 and US 113 Alternate remained north of Dover until 1974, when AASHTO approved moving the northern terminus of US 113 to the junction of US 13 and Bay Road. The organization also approved removing US 113 Alternate from State Street north of US 13 and instead following US 13 to US 113's northern terminus. US 113 Alternate was removed as an alternate route in conjunction with the elimination of US 113 between Milford and Dover after AASHTO approved the moves at the organization's 2003 annual meeting. The portions of US 113 Alternate that were not concurrent with US 13 or DE 10 Alternate became unnumbered.