The DE 1 freeway between Dover Air Force Base and Christiana opened in multiple stages between 1991 and 2003, and at a cost of $900 million was the largest public works project in Delaware history.

The route becomes a freeway near Magnolia and turns into a toll road called the Korean War Veterans Memorial Highway while passing Dover Air Force Base.

The road continues north into the town of Fenwick Island and heads through business areas with some residences a short distance to the west of the Atlantic Ocean.

The route heads past a small area of residential development before it goes through more of the state park, running to the west of a fire control tower from World War II.

DE 1 leaves South Bethany and heads into commercial areas in the community of Middlesex Beach, briefly curving northwest before turning north again.

Continuing north, DE 1 becomes Coastal Highway again and heads past the community of Sussex Shores, running between wooded areas to the west and beachfront homes to the east.

Farther north, the route crosses into Delaware Seashore State Park, where it travels along a strip of land between the Indian River Bay to the west and the Atlantic Ocean to the east.

At this point, DE 1 becomes concurrent with US 9, and the two routes run through woods before curving west past businesses and passing north of the Lewes Transit Center park and ride serving DART First State buses.

Past Five Points, DE 1 narrows back to four lanes and heads south of a park and pool lot located at a church before it bypasses the community of Nassau to the southwest, curving northwest to pass over the Georgetown-Lewes Trail on a bridge.

[5][6] After the bridge over the trail, DE 1 leaves the Delaware Beaches resort area and heads into a mix of farm fields and residential and commercial development, coming to a junction with Minos Conaway Road and traveling to the northeast of Red Mill Pond.

The route passes between residential development to the west and farmland to the east before turning northwest into wooded areas and coming to a diamond interchange with DE 36.

Past this interchange, DE 1 becomes Bay Road and crosses Swan Creek to the east of Tub Mill Pond before it runs through a mix of farm fields and residential and commercial areas.

Following this interchange, the toll road leaves Dover and crosses Dyke Branch as it continues through wooded areas with some fields and nearby development.

The highway runs along the eastern edge of Smyrna and crosses Mill Creek, heading between residential development to the west and rural land to the east and passing under DE 6 with no access.

The freeway continues northwest through rural areas to the west of US 13, curving north and crossing over Sandom Branch and US 13 to briefly travel along the east side of the U.S. highway.

The freeway continues north a short distance to the east of US 13 past residential subdivisions as it comes to a diamond interchange with Pole Bridge Road, which heads west to intersect US 13 and the southern terminus of DE 896 in the community of Boyds Corner.

US 13/DE 1 cross Red Lion Creek and continue concurrent to the community of Tybouts Corner, where DE 1 splits at an interchange to remain as a freeway and US 13 heads northeast as a divided highway with at-grade intersections.

[18] On August 1, 2014, the weekend tolls at Dover and Biddles Corner increased to $3 for passenger vehicles in order to again provide funding to transportation projects across the state.

The highway was proposed as a modern road that would improve travel and bring economic development to Kent and Sussex counties as part of a philanthropic measure.

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.

[34][35] US 113 between Little Heaven and Dover Air Force Base was expanded to a divided highway in 1984 and 1985; this project included replacing the two-lane drawbridge over the St. Jones River with a four-lane girder bridge.

[78] On October 27, 2008, construction began on an interchange at DE 9 near Dover Air Force Base, with Governor Ruth Ann Minner in attendance at the groundbreaking ceremony.

[95][96] A ribbon-cutting ceremony for this interchange was held on August 10, 2018, with Governor Carney, Senator Carper, U.S. Representative Lisa Blunt Rochester, and DelDOT secretary Cohan in attendance.

[99] A ribbon-cutting ceremony for the DE 14 interchange took place on May 18, 2019, with DelDOT secretary Cohan, Senator Carper, and State Representative Bryan Shupe in attendance.

[110][111] In 2021, plans were made to construct a median fence along DE 1 between Read Avenue and Saulsbury Street in Dewey Beach, which is aimed to direct pedestrians to cross the roadway at crosswalks.

[73][114][115] On June 21, 2022, a groundbreaking ceremony was held to mark the beginning of construction of an interchange with DE 16 east of Milton, with Governor Carney, DelDOT secretary Nicole Majeski, and state and local officials in attendance.

The toll road would head south from Ogletown and cross the Chesapeake & Delaware Canal on the Summit Bridge to reach a connector to US 301 near the Maryland state line.

[141] In December 1995, the section of DE 1 between US 13 in St. Georges and US 13 in Tybouts Corner opened, which included the Chesapeake & Delaware Canal Bridge (now called the Senator William V. Roth Jr.

[171] On December 24, 2018, a replacement entrance ramp from US 13 to northbound DE 1 in St. Georges was opened, located further south to the Biddles Corner mainline toll plaza.

passes to the west of Milford High School and heads north to an intersection with US 113, at which point it becomes concurrent with that route on four-lane divided Dupont Boulevard.