U.S. Route 13 in Delaware partially coincident with Delaware Route 1
U.S. Route 13 (US 13)  is a U.S. highway running from Fayetteville, North Carolina, north to Morrisville, Pennsylvania. In the U.S. state of Delaware, the route runs for  103.33 mi (166.29 km). It traverses the entire north–south length of the state from the Maryland state line in Delmar, Sussex County, north to the Pennsylvania state line in Claymont, New Castle County. US 13 connects many important cities and towns in Delaware, including Seaford, Dover, and Wilmington. The entire length of US 13 in Delaware is a multilane divided highway with the exceptions of the segment through Wilmington and parts of the route in Claymont. Between the Maryland state line and Dover, US 13 serves as one of the main north–south routes across the Delmarva Peninsula. From Dover north to Tybouts Corner, the route is followed by the controlled-access Delaware Route 1 (DE 1) toll road, which crosses the route multiple times and has multiple interchanges with it. US 13 bypasses downtown Wilmington to the east before it heads northeast of the city parallel to Interstate 495 (I-495) and the Delaware River to Claymont. US 13 is the longest numbered highway in the state of Delaware.
The portion of US 13 between Delmar and Dover was constructed as a state highway during the 1920s. Between Dover and Wilmington, the route was built as part of the cross-state DuPont Highway, which was completed in 1923 and improved transportation between northern and southern Delaware. North of Wilmington, what would become US 13 was originally built as the Philadelphia Pike in the 1820s and improved to a state highway by 1920. US 13 was designated through Delaware when the U.S. Highway System was created in 1926. The route was widened into a divided highway between Dover and Wilmington in the 1930s and between Delmar and Dover in the 1950s. US 13 was routed to bypass Dover in the 1950s. In 1970, US 13 was moved to its current alignment between Wilmington and Claymont on a bypass built in the 1930s. The portion of US 13 between Dover and Wilmington saw heavy traffic heading to the Delaware Beaches in the summer, which led to the construction of a freeway "Relief Route" parallel to US 13. This freeway was built as DE 1, which was completed in 2003. The construction of DE 1 necessitated the realignment of US 13 in two places.Route description
US 13 enters Delaware from Maryland in Delmar and heads north through Sussex County as a multilane divided highway called Sussex Highway, passing through rural areas and various cities and towns including Laurel, Seaford, Bridgeville, and Greenwood. The route continues into Kent County, where it becomes Dupont Highway and runs north through Harrington, Felton, and Camden. US 13 passes through the city of Dover, where it heads through commercial areas. Past Dover, the route is paralleled by the controlled-access DE 1 toll road and comes to Smyrna, where it enters New Castle County. Here, US 13 continues north and crosses DE 1 multiple times, passing through Odessa. The route crosses the Chesapeake & Delaware Canal on the St. Georges Bridge before it runs concurrent with the DE 1 freeway between Wrangle Hill and Tybouts Corner. Upon splitting from DE 1, US 13 heads northeast through suburban areas along the multilane divided Dupont Highway, forming a concurrency with US 40 in the New Castle area. The route passes through the eastern part of the city of Wilmington on city streets, including a one-way pair. Upon leaving Wilmington, US 13 becomes a multilane divided highway called Governor Printz Boulevard and runs northeast parallel to I-495 and the Delaware River to Claymont, where it follows Philadelphia Pike to the Pennsylvania state line.The section of US 13 south of Tybouts Corner serves as part of a primary hurricane evacuation route from coastal areas of the Delmarva Peninsula to inland areas to the north. Portions of US 13 in Delaware are designated as part of the Delaware Byways system. The segments between US 13 Alt. (North State Street) in Dover and Main Street in Smyrna, DE 9 (New Castle Avenue) and A Street in Wilmington, and Swedes Landing Road and DE 9 (4th Street) in Wilmington are part of the Harriet Tubman Underground Railroad Byway. The section of US 13 in Delaware between US 13 Bus. (Philadelphia Pike) and the Pennsylvania state line in Claymont is part of the Washington–Rochambeau Revolutionary Route, a National Historic Trail. US 13 in Delaware has an annual average daily traffic count ranging from a high of 77,363 vehicles at the US 202/DE 141 interchange near New Castle to a low of 4,096 vehicles at the southern border of Wilmington. US 13 in Delaware is a part of the National Highway System between the Maryland state line in Delmar and the Puncheon Run Connector freeway in Dover, from DE 1 in Wrangle Hill to I-495 in Minquadale, and between DE 92 and the Pennsylvania state line in Claymont. US 13 in Delaware is designated as a Blue Star Memorial Highway honoring those who have served in the United States Armed Forces; Blue Star Memorial Highway markers are located at the Smyrna Rest Area and in Seaford. The route was designated as a Blue Star Memorial Highway between the Maryland state line and Dover in 1981 and between Dover and the Pennsylvania state line in 1998.New Castle County
US 13 crosses the Duck Creek into New Castle County, where it heads through rural residential and commercial development and leaves Smyrna. The name changes to Dupont Parkway and the road passes to the west of the Smyrna Rest Area accessible from both directions before it comes to an interchange with DE 1, at which point the freeway crosses US 13. The highway continues northwest through wooded areas with some farm fields and homes. US 13 passes a northbound weigh station before it heads across Sandom Branch and under the DE 1 freeway. The route runs through the community of Blackbird and crosses the Blackbird Creek before it curves north and comes to an intersection with the southern terminus of DE 71 at H and H Corner; DE 71 heads northwest to the town of Townsend. A short distance past this junction, the road passes under DE 1 again and crosses Herring Run. The highway continues through woodland and development before it intersects Pine Tree Road/Blackbird Landing Road, where there is a park and pool lot on the northwest corner of the intersection. From here, the road runs immediately to the east of DE 1, passing through the community of Fieldsboro and running near residential subdivisions. DE 1 curves northwest away from US 13, with US 13 crossing the Appoquinimink River and heading into residential areas.The route passes west of a park and pool lot and enters the town of Odessa, where the median widens to include development within it and the road curves to the northeast. In Odessa, US 13 is known as 5th Street northbound and 6th Street southbound in addition to Dupont Parkway. Through the town, the route passes homes and a few businesses, crossing DE 299. Upon leaving Odessa, the median narrows again and US 13 continues into rural areas along Dupont Parkway, passing under DE 1. The road curves north and crosses Drawyer Creek a short distance to the west of DE 1. The highway runs through a mix of farmland and residential subdivisions before it comes to an intersection with the southern terminus of DE 896 and Pole Bridge Road in Boyds Corner, with Pole Bridge Road heading east to an interchange with DE 1. Following this, US 13 passes under DE 1 again and runs through more farmland a short distance to the east of the Biddles Corner toll plaza on DE 1. As the highway approaches the community of St. Georges, a partial interchange provides access to and from the northbound direction of DE 1; the ramp from southbound DE 1 connects to US 13 by way of Lorewood Grove Road while there is a direct ramp from US 13 to northbound DE 1 at the Port Penn Road intersection in Biddles Corner that merges with the ramp from the northbound direction of the US 301 toll road to northbound DE 1. A right-in/right-out interchange connects to South Main Street northbound and Lorewood Grove Road southbound to provide access to South St. Georges.
partially overlapping with partially intersecting with partially sharing with partially matching with partially aligning with