 The portion of DE 1 between Little Heaven and Dover Air Force Base was built as part of a Dover bypass for US 113 . This bypass was built atop existing Bay Road north of the present @-@ day DE 9 interchange and on a new alignment south of there . The new highway between Little Heaven and Bay Road would cross the St. Jones River at a site called Barkers Landing . Between December 1931 and the end of 1933 , DSHD constructed a causeway across 3 @,@ 150 feet ( 960 m ) of the marsh on the east bank of the river , a process that required multiple applications of fill dirt and dynamite to create a stable surface for a modern highway . A Scherzer rolling lift bascule bridge was constructed across the St. Jones River in 1934 . Bay Road was widened and the new sections of highway were built with 20 @-@ foot ( 6 @.@ 1 m ) wide concrete pavement starting in 1934 . US 113 was relocated to the bypass when the new highway opened for Memorial Day in 1935 . 
