Maryland Route 355 (MD 355) is a 36.75-mile (59.14 km) north–south road in western central Maryland in the United States. The southern terminus of the route is Friendship Heights, the border between Washington, D.C. and Bethesda, Maryland. From there it continues south as Wisconsin Avenue into Washington. The northern terminus is just north of an overpass with Interstate 70 (I-70) and U.S. Route 40 (US 40) in the city of Frederick in Frederick County, where the road continues north through Frederick towards MD 26. MD 355 serves as a major thoroughfare through Frederick and Montgomery counties, passing through Bethesda, Rockville, Gaithersburg, Germantown, Clarksburg, Hyattstown, Urbana, and Frederick, roughly parallel to I-270. The southern portion of the route from the D.C. border to Germantown is a suburban four- to six-lane divided highway lined with many businesses. North of Germantown, the route is predominantly a two lane rural road until it reaches Frederick, where it passes through commercial areas in the southern part of the city.
MD 355 is the original route of US 240, which was planned in 1926 to run from Washington, D.C. north to Harrisburg, Pennsylvania; however, the route was designated a part of US 15 north of Frederick. This route served as the primary connector linking Frederick and points west to Washington, D.C. During the 1950s, US 240 was relocated in stages to the Washington National Pike, a freeway between Bethesda and Frederick shared with I-70S (now I-270). MD 355 was designated onto the former alignment of US 240 between Bethesda and Frederick as each stage of freeway was built. MD 355 was also designated through Frederick along Market Street, which was the former alignment of US 15 through the city before it was moved to a bypass in 1959. US 240 was decommissioned in 1972, and MD 355 was extended south along the former US 240 to the Washington, D.C. border. In 2006, the interchange with US 15 at the route’s northern terminus was removed, resulting in MD 355 ending just short of US 15 at a dead end. By 2009, a four lane divided bypass of Urbana for MD 355, funded by private developers, was completed. The former alignment of MD 355 through Urbana was designated as MD 355 Business (MD 355 Bus.) The same year, the portion of MD 355 north of I-70 was transferred to the city of Frederick and is no longer considered part of the route.
MD 355 is a part of the main National Highway System from the District of Columbia in Friendship Heights to I-495 in Bethesda. The highway is also a part of the National Highway System as an intermodal connector from I-495 to Shady Grove Road in Rockville and as a principal arterial from Shady Grove Road to MD 27 in Germantown.
MD 355 begins in Friendship Heights, Montgomery County at the intersection with Western Avenue NW and Military Road NW on the border of Washington D.C.. It heads north from this point on Wisconsin Avenue, a six-lane divided highway. Wisconsin Avenue continues south into Washington, ending in Georgetown at an intersection with K Street underneath the Whitehurst Freeway just north of the Potomac River. From the D.C. border, MD 355 heads north through areas of retail and high-rise buildings in Friendship Heights including The Shops at Wisconsin Place that are served by the Red Line of the Washington Metro. Past Friendship Heights, the route continues into wooded residential areas of Somerset before passing the Chevy Chase Country Club on the east side of the road and residential areas of Chevy Chase to the west. It comes to an intersection with MD 191 (Bradley Boulevard / Bradley Lane). Past this intersection, MD 355 enters Bethesda, where it heads back into commercial areas with high-rise buildings.
In downtown Bethesda, the road intersects MD 410 (Montgomery Avenue) one-way eastbound and the westbound direction of MD 410 (East West Highway) and MD 187 (Old Georgetown Road) a short distance further on, near the Bethesda Metro station. The road continues through the community and passes by Bethesda Theatre, a 1938 Art Deco cinema. It leaves the downtown area of Bethesda and becomes Rockville Pike at the intersection with Glenbrook Parkway / Woodmont Avenue. From here, the road passes the Walter Reed National Military Medical Center, one of the United States' most prominent military hospitals, and the National Institutes of Health, which is home to the United States National Library of Medicine, the world’s largest medical library.
Past the naval hospital and the NIH, the road intersects Cedar Lane. After this intersection, it heads north into wooded areas, passing near residences as well as the Bethesda Meeting House, an 1850 wood-frame church. MD 355 continues north through more suburban residential areas before coming to an interchange that provides access to I-495 (Capital Beltway) and the southern terminus of I-270. Past this interchange, the road skirts the edge of Rock Creek Park, passing by the Linden Oak at the Grosvenor Lane intersection. MD 355 continues into residential areas of North Bethesda, where the Metro Red Line briefly comes above the surface and parallels the route to the east adjacent to the Grosvenor–Strathmore Metro station before the intersection with MD 547 (Strathmore Avenue).
The route heads through some residential neighborhoods before entering a commercial area with strip malls and some high-rise buildings where White Flint Mall, once one of the D.C. metropolitan area's largest shopping malls, was located on the east side of the road. The road comes to another intersection with MD 187 (Old Georgetown Road) as well as a newly grade-separated interchange at Montrose Parkway. The Metro Red Line draws farther east from MD 355 before it crosses into Rockville, the county seat of Montgomery County. In Rockville, the road passes more commercial development with a railroad line paralleling the road a short distance to the east. The route intersects MD 911 (First Street) and the Wootton Parkway. MD 355 intersects MD 660 (Dodge Street), which is a short connector to MD 28 (Veirs Mill Road) that the route intersects a short distance later.
Past this intersection, MD 355 continues into downtown Rockville, where it becomes Hungerford Drive. The road passes by the Rockville train station, which is used by the Metro’s Red line, MARC’s Brunswick Line, and Amtrak’s Capitol Limited. MD 355 heads into more commercial areas and passes the Rockville campus of Montgomery College before intersecting Gude Drive. Past this intersection, MD 355 becomes Frederick Road and heads northwest into a mix of commercial and residential areas in Derwood, drawing further away from the railroad tracks. The route leaves Rockville and intersects Shady Grove Road. Past Shady Grove Road, MD 355 interchanges with I-370 and crosses into Gaithersburg. Here, the road heads through more commercial areas before heading into residential neighborhoods. It heads into business areas again as it approaches downtown Gaithersburg, where the route interchanges with MD 117 (Diamond Avenue) and continues northwest past more businesses. MD 355 passes the Lakeforest Mall before intersecting MD 124 (Montgomery Village Avenue). MD 355 passes more strip malls past this intersection before crossing over Great Seneca Creek and leaving Gaithersburg. The route continues northwest into Germantown through residential areas before passing businesses again and intersecting Middlebrook Road. It passes through residential developments, with the road narrowing to four lanes before it reaches an intersection with MD 118 (Germantown Road). From here, the road passes more homes and a shopping center prior to crossing MD 27 (Ridge Road).
Past MD 27, the road passes more suburban developments before narrowing to a two-lane undivided road and heading through some woodland. It continues northwest through a mix of rural woodland and suburban development in Clarksburg, where MD 355 intersects MD 121 (Clarksburg Road). Past this intersection, the route passes Little Bennett Regional Park on the east and businesses on the west, running closely parallel to I-270 located to the west. The route eventually draws farther east of I-270 and heads through residential neighborhoods and woodland before reaching Hyattstown. In Hyattstown, MD 355 intersects MD 109 (Old Hundred Road).
After passing through Hyattstown, MD 355 crosses into Frederick County, where it becomes Urbana Pike. Here, it passes some businesses before intersecting MD 75 (Green Valley Road). Past this intersection, the road continues into a more rural setting consisting of farmland, woods, and some residential areas and businesses. The route reaches Urbana, where it heads onto a four lane divided bypass called Worthington Boulevard to the east of the community, while the former alignment of MD 355 continues through Urbana as MD 355 Bus. MD 355 intersects MD 80 (Fingerboard Road) and passes through residential areas in the Villages of Urbana subdivision, encountering two roundabouts. Upon leaving Urbana, the route intersects MD 355 Bus. again and returns to its original alignment on two-lane undivided Urbana Pike as it continues north through areas of woods and farms with some rural residences. The road passes Monocacy National Battlefield, the site of the Battle of Monocacy Junction in the American Civil War fought on July 9, 1864. Past the battlefield, the road crosses the Monocacy River and a CSX railroad line.
In a short distance, MD 355 heads from rural areas into a commercial district on the outskirts of Frederick. The road widens to four lanes as it passes by the Francis Scott Key Mall and several other businesses. It intersects MD 85 (Buckeystown Pike), which provides access to and from I-70 and US 40. MD 355 passes over I-70/US 40 and ends just north of the overpass, with the road continuing north into Frederick as locally maintained Market Street.
The Rockville Pike portion of MD 355 dates back to colonial times and was used as an escape route from Washington during the War of 1812 as well as a route for settlers to travel from Montgomery County to developing areas north and west. In 1911, a small portion of state highway leading northwest out of Rockville was completed, with the remainder between Rockville and Gaithersburg under contract. A state highway was proposed between Gaithersburg and Germantown. The state road between Gaithersburg and Germantown was finished by 1915. By 1921, the portions of state highway between the Washington, D.C. border and Rockville, to the northwest of Germantown, and between northwest of Urbana and Frederick were completed. At this time, a state highway was proposed between northwest of Germantown and northwest of Urbana. The state road was completed between Germantown and Clarksburg and through Urbana to a point southeast of the community by 1923. The entire length of the state road connecting Washington, D.C. and Frederick was completed by 1927. In the approved plan for the U.S. Highway System in 1926, US 240 was planned to run from Washington, D.C. to Harrisburg, Pennsylvania via Frederick. In 1927, US 240 was designated along the proposed 1926 route south of US 15/US 40 in Frederick with the US 15 designation given to the road north of Frederick. In 1950, US 240 was widened into a divided highway between the Washington, D.C. border and Bethesda.
In 1947, plans were made to construct a freeway, the Washington National Pike (now I-270), parallel to US 240. In 1953, the US 240 freeway was completed between MD 121 in Clarksburg and US 15 (now MD 85) in Frederick. The former alignment of US 240 between Clarksburg and Frederick was designated as US 240 Alt. A year later, the freeway was extended down to MD 118 in Germantown. At this time, the original alignment between Germantown and Frederick was designated MD 355, replacing what was US 240 between Germantown and Clarksburg and the entire length of US 240 Alt. between Clarksburg and Frederick. The US 240 freeway was extended south to MD 28 in Rockville in 1956, and MD 355 was subsequently extended south along the former alignment to the MD 28 intersection in Rockville. Also, the US 240 freeway was completed from US 15 north to US 40. In 1957, US 240 was upgraded to a divided highway between Bethesda and Rockville. The US 240 freeway was extended south to Montrose Road in 1958, resulting in MD 355 being extended south along the former alignment to Montrose Road. I-70S was designated onto the US 240 freeway in 1959. In addition, MD 355 was extended north to US 15 north of Frederick, passing through the city on Market Street, the one-way pair of Market Street northbound and Bentz Street southbound in the downtown, and Market Street to the north of downtown. The route replaced US 15/US 240 south of downtown Fredrick and US 15 north of downtown Frederick, with US 15 shifted to a bypass west of the city. In 1960, I-70S/US 240 was extended south to the Capital Beltway, and MD 355 was extended south along former US 240 between Montrose Road and the Capital Beltway.
In 1972, the American Association of State Highway Officials approved for the US 240 designation to be removed. As a result, MD 355 was extended south along the former US 240 alignment to the Washington, D.C. border. MD 355 was widened into a divided highway between Rockville and Gaithersburg in 1977. The divided highway was extended north from Gaithersburg to Germantown by 1997. In 2006, the northern terminus of MD 355 at the interchange with US 15 in Frederick was truncated to a dead end a short distance south of that route. In 2009, the portion of MD 355 north of the I-70 overpass was transferred to the city of Frederick, with the MD 355 designation officially being removed from this stretch. In 2010, an interchange was completed at Montrose Parkway.
A four-lane divided bypass of Urbana was constructed for MD 355 in the 2000s. The primary reason for constructing the bypass was to relieve traffic heading through the community brought on by the construction of numerous shopping centers in the area, and the costs for constructing the bypass were entirely paid for by the developers of an area shopping center. The proposal for the bypass called for two roundabouts to control traffic. The first portion of the road opened in late 2005 from MD 355 south to a roundabout at Sugarloaf Parkway. On October 30, 2008, construction began to build the connection of the bypass to MD 355 south of MD 80. The bypass was completed by January 2009, at which point MD 355 was realigned onto it and the former alignment became MD 355 Bus. In 2013, maintenance of the bypass of MD 355 around Urbana was transferred from the developers to the state.
Maryland Route 355 Business (MD 355 Bus.) is the designation of a 1.06-mile (1.71 km) business route of MD 355 in Urbana that runs along Urbana Pike. The route begins at MD 355 south of Urbana, heading west as a two-lane undivided road and coming to an intersection with MD 80. Past this intersection, the road continues northwest through residential areas. The business route reaches its terminus at another intersection with MD 355. The entire length of MD 355 Bus. originally followed MD 355C. In 2014, all of MD 355C except for a 0.376-mile (0.605 km) portion between a point south of Urbana Church Road and Sprigg Street was turned over to county maintenance.
Junction listMD 355A runs along an unnamed road from MD 355 north to a cul-de-sac in Frederick, Frederick County. The route is 0.05 mi (0.080 km) long.
MD 355B ran along an unnamed road from MD 355 Business east to a dead end in Urbana, Frederick County. The route was 0.12 mi (0.19 km) long. MD 355B was turned over to county maintenance in 2014.
The entire route is in Urbana, Frederick County.