Maryland Route 650 partially coincident with New Hampshire Avenue
Maryland Route 650 (MD 650) is a state highway in the U.S. state of Maryland.  Known as New Hampshire Avenue for most of its length, the state highway runs 25.89 mi (41.67 km) from Eastern Avenue at the Washington, D.C. border north to MD 108 in Etchison.  MD 650 serves as a major north-south commuter route in northwestern Prince George's County and eastern Montgomery County, connecting the District of Columbia with the residential suburbs of Takoma Park, Langley Park, Adelphi, Hillandale, White Oak, and Colesville.  By contrast, the part of MD 650 north of Spencerville is a quiet rural road connecting several small communities along the northeastern fringe of Montgomery County.
MD 650 was originally built between Takoma Park and Adelphi in the late 1930s as an extension of New Hampshire Avenue out of Washington.  In the 1950s, the state highway was extended north, taking over portions of MD 320 and U.S. Route 29 (US 29) and all of MD 116.  Beginning in the 1950s and continuing through the 1990s, MD 650 has been expanded to a multi-lane divided highway in stages from its southern terminus north to Spencerville.Route description
MD 650 is a part of the National Highway System as a principal arterial from its southern terminus north to MD 108 in Ashton.Takoma Park to White Oak
MD 650 begins at Eastern Avenue on the border of Washington, D.C.  New Hampshire Avenue continues south into the District of Columbia.  MD 650 heads northeast as a six-lane divided highway lined with shopping centers.  The state highway straddles the border between Prince George's County on the east and Montgomery County on the west, as well as the eastern border of the city of Takoma Park.  MD 650 intersects Poplar Avenue and Ray Road, which were formerly MD 204, before the present state highway meets MD 410, which heads west as Ethan Allen Avenue and east as East–West Highway.  After crossing MD 410, MD 650 fully enters both Takoma Park and Montgomery County.  The state highway heads into a forested area with some residences, where it intersects Sligo Creek Parkway and the Sligo Creek Trail on a bridge crossing Sligo Creek.  MD 650 continues into an area of apartment buildings and single family residences, then passes between a couple of shopping centers before intersecting MD 193 (University Boulevard) in Langley Park, where the Takoma Langley Crossroads Transit Center is located at the northwest corner of the intersection.History
MD 650 began as a continuation of New Hampshire Avenue out of Washington.  The state highway was planned by 1935 roughly following Sligo Mill Road to the site of the defunct mill at the current intersection with Sligo Creek Parkway, then east to near the intersection of MD 193 and MD 212 in Langley Park.  By 1939, MD 650 was complete between Eastern Avenue and MD 193, but along its present alignment.  The segment between MD 193 and MD 320 had also started construction, which was complete by 1946.The remainder of the current alignment resulted from MD 650 taking over parts of three other routes between 1955 and 1960: MD 320, US 29, and MD 116 (Damascus Road).  MD 320 continued north from its eastern terminus to the current intersection with Lockwood Drive in White Oak.  From there, US 29 used Colesville Road through the namesake village up to Ashton, where the federal highway used the route of present-day MD 108 east to Ellicott City.  MD 116 continued north and west to the present northern terminus of MD 650.  MD 116 originally only went from Ashton north to Brighton in 1930, but the former state highway was extended north to Sunshine in 1949 and Etchison in 1956.MD 650 assumed MD 320's route north to White Oak in 1955.  The next year, the original portion of MD 650 was rebuilt as a multi-lane divided highway.  In 1960, MD 650 took over the old route of US 29 between White Oak and Ashton when US 29 was shifted to the new Columbia Pike, then took over all of MD 116.  The divided highway was extended to White Oak in the 1960s, to Colesville in the 1970s, and to Spencerville in the 1990s.
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