Maryland Route 320

Maryland Route 320
Piney Branch Road
Maryland Route 320 highlighted in red
Route information
Maintained by MDSHA
Length:	2.84 mi (4.57 km)
Existed:	1927 – present
Major junctions
South end:	Piney Branch Road at the District of Columbia boundary in Takoma Park
	MD 410 in Takoma Park MD 193 in Silver Spring
North end:	MD 650 in Adelphi
Location
Counties:	Montgomery, Prince George's
Highway system
Maryland highway system Interstate US State Scenic Byways ← MD 318 MD 322 →

Maryland Route 320 (MD 320) is a state highway in the U.S. state of Maryland. Known as Piney Branch Road, the highway runs 2.84 miles (4.57 km) from Eastern Avenue at the District of Columbia boundary in Takoma Park north to MD 650 in Adelphi. MD 320 is a southwest–northeast highway that connects Takoma Park and Silver Spring in southeastern Montgomery County with Adelphi in far western Prince George's County. The state highway originally extended from downtown Silver Spring to White Oak and connected with U.S. Route 29 (US 29) at both ends. The Silver Spring–Adelphi portion of the highway was constructed by 1910. The segment through Takoma Park and the Adelphi–White Oak segment, which later became MD 650, were built in the early 1930s; the Takoma Park portion was built as MD 513. MD 320 was widened over its whole length in the late 1940s and reduced to its present course in the mid-1950s.

MD 320 begins at the intersection of Piney Branch Road and Eastern Avenue at the District of Columbia boundary in the city of Takoma Park. Piney Branch Road continues southwest into Washington, where it immediately passes under CSX's Metropolitan Subdivision and the Washington Metro's Red Line. Eastern Avenue provides access to the Takoma station on the Red Line and the Takoma Park Historic District to the southeast; the street also leads to the Takoma Park/Silver Spring campus of Montgomery College to the northwest. MD 320 heads northeast as a narrow two-lane road. The highway expands as it veers north at one-way Chestnut Avenue and intersects MD 410 (Philadelphia Avenue). The highway curves northeast and gains a center turn lane as it leaves the city of Takoma Park and passes Takoma Park Middle School.