US 40 was also designated to run along the entire length of the route between Penns Grove and Atlantic City.

Route 48 was designated onto its current alignment in 1953, eliminating the concurrency it shared with US 40 from Carneys Point Township to Atlantic City.

Route 48 begins at a traffic light with US 130 and CR 675 in Penns Grove, heading to the southeast on Main Street, a two-lane, undivided road.

[1] Route 48 continues southeast through a mix of woodland and farmland, intersecting CR 551 at a traffic light.

[1][2] Route 48 continues southeast for about another mile, crossing Stumpy Road before ending at an intersection with US 40.

[4][5] Until the Delaware Memorial Bridge opened in 1951, a ferry connected Route 48 to DE 48 in Wilmington.