The state highway is a part of the National Highway System between I-97 and the entrance to the Cromwell Station / Glen Burnie station of the Baltimore Light Rail.
Maryland | University of Maryland | Bethesda, Maryland | Annapolis, Maryland | Silver Spring, Maryland | Montgomery County, Maryland | U.S. Route 66 | U.S. Route 1 | Cumberland, Maryland | Governor of Maryland | Frederick, Maryland | Maryland House of Delegates | Hagerstown, Maryland | U.S. Route 6 | U.S. Route 101 | Route 66 | Emmitsburg, Maryland | Columbia, Maryland | Westminster, Maryland | U.S. Route 30 | New Jersey Route 4 | European route E65 | U.S. Route 40 | Laurel, Maryland | Howard County, Maryland | Havre de Grace, Maryland | California State Route 1 | University of Maryland, Baltimore | Bowie, Maryland | U.S. Route 1 in Maine |
Immediately after, MD 3 Business intersects MD 648 (Baltimore–Annapolis Boulevard), the former alignment of MD 2, which provides access to the Baltimore Light Rail.