MD 355 — LLMpedia

MD 355
State	MD
Type	MD
Route	355
Length mi	35.89
Direction a	South
Terminus a	Washington, D.C.
Direction b	North
Terminus b	Frederick, Maryland
Counties	Montgomery County, Maryland, Frederick County, Maryland

Contents

MD 355 is a major north–south highway in Maryland. The route links central Washington, D.C. suburbs with downtown Frederick, Maryland, serving as an arterial corridor through communities such as Bethesda, Maryland, Rockville, Maryland, Gaithersburg, Maryland, and Germantown, Maryland. MD 355 parallels parts of the I‑270 corridor and interconnects with highways including U.S. Route 15, U.S. Route 29, and U.S. Route 240.

Route description

The highway begins at the Washington, D.C. boundary near Friendship Heights, Washington, D.C. and proceeds north through Chevy Chase, Maryland and Bethesda, Maryland, passing landmarks such as the National Institutes of Health and Walter Reed National Military Medical Center. Continuing into Rockville, Maryland, MD 355 intersects the Capital Beltway, Interstate 370, and provides access to the Montgomery College campuses and the Rockville Town Square. Northward, the route traverses Gaithersburg, Maryland and Germantown, Maryland, crossing the Metropolitan Branch Trail, the CSX Transportation rail corridor, and aligning near Shady Grove Metro Station. Beyond Clarksburg, Maryland, the roadway enters Frederick County, Maryland and terminates in Frederick, Maryland near U.S. Route 15 and the MD 26 junction, passing cultural nodes like the National Museum of Civil War Medicine and proximity to the Monocacy National Battlefield.

The corridor originated as part of historic turnpikes and plank roads connecting Washington, D.C. to Frederick, Maryland and earlier colonial roads used during the American Revolutionary War and the War of 1812. In the 19th century the route was associated with stagecoach lines serving Baltimore, Maryland and Annapolis, Maryland. State designation and modernization occurred during the 20th century amid progressive era roadway programs influenced by policymakers from Maryland Department of Transportation and planners connected to the Frederick County Board of County Commissioners and Montgomery County Council. Midcentury expansions paralleled federal investments such as the Interstate Highway System and were shaped by traffic planning decisions linked to figures in Federal Highway Administration history. Late 20th-century suburbanization driven by employers like Lockheed Martin, Booz Allen Hamilton, and institutions such as the National Institutes of Health increased corridor demand, prompting interchange projects with I‑270 and local bypass proposals considered by the Montgomery County Planning Board and Frederick County Planning Commission.

Major intersections along the corridor include connections with Wisconsin Avenue, the Capital Beltway at related nodes, the Interstate 370, Interstate 270, U.S. Route 29, Georgia Avenue at shared urban junctions, and northern termini near U.S. Route 15 and MD 26. Other important cross streets are under the jurisdiction of local entities like City of Rockville, Maryland and Montgomery County, Maryland transportation departments, and federal facilities including Walter Reed National Military Medical Center influence lane configurations and signal timing at several intersections.

Several auxiliary and related alignments, created through realignments and business routes, function as connectors and frontage roads serving commercial districts in Bethesda, Rockville, and Gaithersburg. These spurs and business variants provide access to municipal centers such as Rockville Town Square, Old Town Gaithersburg Historic District, and the Frederick Historic District. Maintenance responsibilities are split among the Maryland State Highway Administration, county public works departments in Montgomery County, Maryland and Frederick County, Maryland, and municipal roadway divisions in places like Frederick, Maryland and Germantown, Maryland.

Planned improvements have been proposed by the Maryland Department of Transportation and regional planning bodies including the Metropolitan Washington Council of Governments and the National Capital Region Transportation Planning Board. Proposals include intersection upgrades near Shady Grove, multimodal enhancements connecting to the Metro Red Line and MARC Train services at Rockville station, bicycle and pedestrian investments along the Capital Crescent Trail and the Metropolitan Branch Trail, and congestion relief measures aligned with I‑270 corridor planning by the Federal Highway Administration and Maryland Transportation Authority. Public consultations have involved stakeholders such as the Montgomery County Civic Federation, Frederick County Chamber of Commerce, and advocacy organizations including American Association of State Highway and Transportation Officials members.

The highway supports employment centers tied to institutions like the National Institutes of Health, Food and Drug Administration, U.S. Department of Health and Human Services, and defense contractors such as General Dynamics. Retail corridors along the route include major shopping centers and municipal downtowns — for example, Bethesda Row, Rockville Town Square, and Rio Washingtonian Center in Gaithersburg, Maryland. Cultural assets adjacent to the roadway include the Strathmore Music Center, the AFI Silver Theatre and Cultural Center, and historical sites tied to the Battle of Antietam region. The route influences commuting patterns for commuters to Washington, D.C. and regional transit hubs like Union Station (Washington, D.C.) and contributes to local tourism economies related to Monocacy National Battlefield and the Frederick Keys baseball events.