At its intersection with Riviera Drive and Bar Harbor Road, the state highway turns west and crosses Stony Creek on a drawbridge.

MD 173 turns north at Solley Road and passes Marley Neck Boulevard before entering the city of Baltimore.

MD 173 crosses CSX's Marley Neck Branch railroad line and expands to a divided highway.

MD 173 intersects CSX's Marley Neck Branch rail line at-grade and enters the neighborhood of Curtis Bay.

The westbound highway has an entrance ramp to I-895 (Harbor Tunnel Thruway) immediately before reaching its northern terminus at MD 2 (Potee Street).

[2][3] MD 173 is part of the National Highway System as an intermodal connector between Quarantine Road in Hawkins Point and Patapsco Avenue in Curtis Bay.

[6] Both streets and Hawkins Point Road were in Anne Arundel County until the Baltimore city limits expanded to their present boundaries in 1919.

[7][8] The pavement was extended from Marley Neck Road to the west side of Stony Creek in Orchard Beach in 1928.

[11][12] The gap in MD 173 between Arundel Cove Avenue and the south end of the Curtis Bay neighborhood was filled in 1935, completing the 15-to-18-foot (4.6 to 5.5 m) wide concrete highway from Baltimore to Fort Smallwood.

[1][21] The state highway was assigned in 2001 when the intersection of MD 173 and Edwin Raynor Boulevard was rebuilt so the roads meet at a right angle.