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 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, which heads northwest to the town of Townsend. A short distance past this intersection, 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. From here, the road runs immediately to the east of DE 1, passing through the community of Fieldsboro and heading near residential subdivisions. DE 1 curves northwest away from US 13, and US 13 crosses the Appoquinimink River and heads into residential areas.