U.S. Route 1 in the District of Columbia

View north along US 1 and I-395 crossing the Potomac River on the 14th Street Bridge

Northbound US 1 and Interstate 395 enter the District of Columbia from Virginia on the 14th Street Bridge. US 1 traffic exits Route 395 from the left to 14th Street, S.W. After 14th Street crosses the National Mall, US 1 turns right onto Constitution Avenue. It then turns left onto 6th Street, N.W., and then right onto Rhode Island Avenue. US 1 continues on Rhode Island Avenue through Northeast Washington and into Maryland.

View south along US 1 on Rhode Island Avenue

Southbound US 1 enters the District of Columbia from Maryland on Rhode Island Avenue. US 1 turns left onto 6th Street, N.W., then right onto L Street, N.W., and then left onto 9th Street, N.W. It enters the Ninth Street Tunnel and joins Interstate 395, which it follows into Virginia.

Northbound US 1 is concurrent with eastbound U.S. Route 50 along Constitution Avenue from 14th Street to 6th Street, N.W., and along 6th Street from Constitution Avenue to New York Avenue, N.W. Southbound US 1 is concurrent with westbound US 50 along L Street between 6th and 9th streets, N.W., and along 9th Street from L Street to Constitution Avenue. Both northbound and southbound US 1 have concurrencies with Interstate 395.

When originally designated in 1926, US 1 entered Washington on Bladensburg Road. The old route then continued on Maryland Avenue and turned south on 1st Street, where it then turns left into the U.S. Capitol grounds. US 1 went around the Capitol making its way to Pennsylvania Avenue. The route continues on Pennsylvania Avenue to 14th Street where it turns south. US 1 then left Washington on 14th Street as it does today. By 1946, US 1 entered from the north using Rhode Island Avenue continuing all the way to 14th Street (via Vermont Avenue). It was shifted to its current alignment by 1967.

The entire route is in the District of Columbia.

Location	mi[2]	km	Destinations	Notes
Potomac River	0.0	0.0	I-395 south / US 1 south – Richmond, Alexandria	Continuation into Virginia
	0.1– 0.4	0.16– 0.64	14th Street Bridges (Arland D. WIlliams Jr. Memorial Bridge / George Mason Memorial Bridge)
East Potomac Park	0.5	0.80	I-395 north – Capitol Hill, Verizon Center, Nationals Park	Northern terminus of concurrency with I-395; Exit 1 on I-395; Northbound exit and southbound entrance
	0.7	1.1	I-395 south (Rochambeau Memorial Bridge)	To HOV 3+ only; Southbound exit and northbound entrance
Washington Channel	0.8	1.3	14th Street Bridges (US 1 span)
Southwest Federal Center	0.9	1.4	Maine Avenue SW	Interchange; No southbound exit
National Mall–Downtown	1.5	2.4	US 50 west (Constitution Avenue NW) / 14th Street NW north	Southern terminus of concurrency with US 50, No left turns
	1.7	2.7	12th Street Expressway / 12th Street NW north	Northern terminus of 12th Street Expressway (one-way northbound)
	2.0	3.2	9th Street Expressway south to I-395 US 1 north / US 50 east	Northern terminus of 9th Street Expressway (one-way southbound) Southern terminus of one-way pairs (6th Street NW north / 9th Street NW south)
Downtown	2.2	3.5	US 1 Alt. north (Pennsylvania Avenue NW)	Southern terminus of US 1 Alternate; Access from US 1 north only
Mount Vernon Square	3.0	4.8	US 50 east (New York Avenue NW) to I-495	Northern terminus of concurrency with US 50
	3.1	5.0	US 1 south / US 50 west (L Street NW)	Northern terminus of one-way pairs
Shaw	3.6	5.8	US 29 (Rhode Island Avenue NW west / 6th Street NW north)
Woodridge	7.0	11.3	US 1 north (Rhode Island Avenue) / Eastern Avenue NE – Baltimore	Continuation into Maryland
1.000 mi = 1.609 km; 1.000 km = 0.621 mi       Concurrency terminus       HOV only       Incomplete access

U.S. Route 1 Alternate
Location	Washington, D.C.–Hyattsville, MD
Length	2.1 mi (3.4 km)

U.S. Route 1 Alternate leaves U.S. Route 1 at New York Avenue, following US 50 east, and rejoins the highway in Hyattsville, Maryland.