Route 54 begins at an intersection with MD 313 in the town of Mardela Springs in Wicomico County, Maryland. MD 313 heads north from the intersection as Sharptown Road and west as a short continuation of Delmar Road west to MD 313's terminus with U.S. Route 50 (US 50, Ocean Gateway). Route 54 heads east as two-lane undivided Delmar Road, passing south of Mardela Middle and High School. The road parallels Barren Creek on the north toward the Delaware state line, crossing Mockingbird Creek. After passing the stone marker indicating the intersection of the Transpeninsular Line with the southern end of the Mason–Dixon Line, the highway enters the southwest corner of Sussex County, Delaware, where it intersects Columbia Road. Route 54 continues east until Old Racetrack Road, where the highway turns southeast toward the state line. At the intersection with Waller Road, the state highway begins to follow the state line, with Sussex County, Delaware on the north side of the road and Wicomico County, Maryland on the south, and MDSHA maintenance begins. Route 54 immediately enters the twin towns of Delmar, Delaware and Delmar, Maryland and the highway's name changes to West State Street. The highway crosses the Delmarva Central Railroad's Delmarva Subdivision track at-grade south of Highball Signall where the name changes to East State Street, and meets MD 675 (Bi-State Boulevard), the old alignment of US 13, in the center of the towns. Route 54 continues east and becomes West Line Road before it intersects US 13, which is known as Sussex Highway in Delaware and Ocean Highway in Maryland. At US 13, the highway leaves Delmar and DelDOT assumes maintenance for the highway.