Clara Barton Parkway

History

Congress approved construction of parkways on both sides of the Potomac River from Great Falls to Fort Washington and Mount Vernon in Maryland and Virginia, respectively, in 1930. Construction on the Maryland side, originally named the George Washington Memorial Parkway, began by 1961. The parkway was completed from its western end at MacArthur Boulevard to the interchange with Cabin John Parkway in 1964, and from Cabin John east to the Glen Echo interchange in 1965.

The Glen Echo interchange was intended as temporary, pending a signalized interchange with an onramp overpass for westbound traffic from MacArthur Boulevard; the concrete overpass bridge was built but the new interchange was never finished due to local objections. Extensions were proposed west to Great Falls and east to Georgetown, where it would connect with the Whitehurst Freeway at the Francis Scott Key Bridge, but these plans were abandoned by 1969.

The parkway was completed in its present form from the Glen Echo interchange to the Chain Bridge in 1970. The Maryland portion was renamed for Clara Barton in 1989.

Route description

The Clara Barton Parkway begins at an intersection with MacArthur Boulevard in Carderock, where MacArthur Boulevard heads west toward Great Falls and the community of Potomac. The parkway initially runs east as a two-lane surface road, then becomes a four-lane freeway before a diamond interchange with an access road to the Carderock Division of the Naval Surface Warfare Center, which houses the David Taylor Model Basin, and the Carderock Recreation Area of the C&O Canal.

East of the naval lab, the roadways split for a six-ramp interchange with I-495 (Capital Beltway); there is no direct access from the parkway westbound to I-495 north or from I-495 south to the parkway eastbound. The roadways rejoin in Cabin John near parking areas for C&O Canal Lock 10, Lock 8, and River Center. A diamond interchange provides access to Cabin John via a road connecting to MacArthur Boulevard. The parkway reduces to one lane eastbound crossing Cabin John Creek, then meets the Cabin John Parkway at a partial interchange.

It passes the historic Union Arch Bridge, which carries the Washington Aqueduct and MacArthur Boulevard. The final interchange provides access to MacArthur Boulevard in Glen Echo, site of Glen Echo Park and Clara Barton National Historic Site, and includes a U-turn ramp from eastbound to westbound, a tight right-turn ramp, and an unused bridge; there is no access from MacArthur Boulevard to the eastbound parkway.

Did You Know?

• The parkway operates as a one-way road between the Glen Echo interchange and its eastern terminus Monday to Friday, with eastbound-only flow from 6:15 a.m. to 10 a.m. and westbound-only from 2:45 p.m. to 7:15 p.m.
• Commercial vehicles are prohibited from the Clara Barton Parkway without a permit from the National Park Service.
• Speed limits on the parkway vary: 30 mph from the western terminus to the Carderock interchange, 50 mph from Carderock to Glen Echo, and 35 mph from Glen Echo to the Chain Bridge.