Interstate 66

Home » Guides » District of Columbia » Interstate 66

Just barely entering the city of Washington, Interstate 66 concludes its relatively short routing in the District of Columbia at U.S. 29 near George Washington University. The freeway enters the city across the Theodore Roosevelt Memorial Bridge and turns northward along the Potomac River Freeway before quickly terminating at K Street east and the Whitehurst Freeway west.

I-66 was originally planned to continue east from the Whitehurst Freeway along the North Leg Freeway, parallel to K Street. The North Leg Freeway would have extended I-66 east to a terminus with I-95 (Center Leg Freeway), a short distance north of where I-395 ends today at New York Avenue (U.S. 50). Provisions in the 1960s were made at the interchange with the Whitehurst Freeway for the North Leg Freeway. Unused ramps here were demolished when the Whitehurst was reconstructed in the late 1990s.1

Interstate 66 utilizes a 0.9-mile portion of the West Leg Freeway, a component of the 1955-planned Washington Inner Loop system.1 The West Leg was to tie into the South Leg Freeway (I-695) running southeast by the Tidal Basin to the present day Maine Avenue ramps from I-395. Directional ramps with Ohio Drive remain from the South Leg Freeway plan.

Work commenced on the Potomac River Freeway section of I-66 in 1960. The Roosevelt Bridge opened in June 1964, but with ramps just to Constitution Avenue (U.S. 50). Progress along I-66 to the north followed with a July 1965 opening to the E Street Expressway. Further work completed by late 1965 included the cut and cover tunnel below Virginia and New Hampshire Avenues to the east of the Watergate Complex.1

Interstate 66 U.S. 50 East
Interstate 66 curves eastward over George Washington Parkway to combine with U.S. 50 east at the Little River, just beyond the D.C. line. The tandem span the Potomac River across the Theodore Roosevelt Bridge.
The Theodore Roosevelt Memorial Bridge, which opened in June 1964, is seven lanes wide, with a reversible median that can be adjusted to accommodate heavier flows in each direction. Photo taken 08/04/13.
Interstate 66 & U.S. 50 combine for just 0.4 miles across the Theodore Roosevelt Bridge. The bridge mainline defaults onto U.S. 50 east for Constitution Avenue NW to the National Mall and Downtown. The left lane(s) continue I-66 east onto the Potomac River Freeway north through Foggy Bottom. Photo taken 08/04/13.
Originally, this bridge was to serve as a gateway to a major freeway corridor, which would follow Interstate 66 (Potomac River Freeway) northeast to U.S. 29, then through a tunnel along K Street (North Leg Freeway) east to a planned terminus with the Center Leg Freeway (I-95), north of where I-395 currently ends at New York Avenue. That tunnel was never constructed, nor was I-95 north of the U.S. 50/I-395 intersection. As a result, the importance of Interstate 66 is more of a feeder route into the Downtown area. Photo taken 08/04/13.
An off-ramp departs for the south end of the Potomac River Freeway ahead of Ohio Drive south to Independence Avenue east. Interstate 66 and U.S. 50 split immediately there after. Independence Avenue extends east from Ohio Drive, south past the Lincoln Memorial, along the south edge of the National Mall.
Surprisingly, this is the final sign (guide sign or reassurance shield) that refers to Interstate 66 east. There are no reassurance shields or any END markers posted along the Potomac River Freeway north. Photo taken 08/04/13.
Interstate 66 East
Eastbound Interstate 66 turns north to join the Potomac River Freeway, a short freeway that was intended to be a much longer route (part of which was proposed as I-70S). Passing under U.S. 50 west, drivers face a quick decision point with the right two lanes defaulting onto the E Street Expressway east to Foggy Bottom and a single lane for I-66 east to U.S. 29 (Whitehurst Freeway). Photo taken 08/04/13.
Interstate 66 joins the Potomac River Freeway at a wide swath of pavement below ramps to E Street Expressway. The next exit departs from the left in one quarter mile for Rock Creek Parkway via 27th Street NW. Exits are unnumbered for I-66 in Washington. Photo taken 08/04/13.
An on-ramp joins I-66 (Potomac River Freeway) east from E Street west ahead of a cut and cover tunnel below New Hampshire and Virginia Avenues. Photo taken 08/04/13.
Forthcoming Rock Creek Parkway meanders alongside Rock Creek from near the Interstate 66 / U.S. 29 interchange north through Kalorama Heights and Adams-Morgan, coming to an end at Connecticut Avenue Northwest. Photo taken 08/04/13.
Interstate 66 passes below the Watergate Complex area through. This stretch of freeway opened last in December 1965. Photo taken 08/04/13.
Beyond the two-lane ramp for Rock Creek Parkway, Interstate 66 east prepares to end at a ramp split for U.S. 29 (Whitehurst Freeway) south to Georgetown and L Street east to Pennsylvania Avenue.
Pennsylvania Avenue leads to U.S. 29 north / K Street, Washington Circle, George Washington University, and the White House. Photo taken 08/04/13.
A weathered guide sign partitions traffic to Whitehurst Freeway west and Pennsylvania Avenue NW. The split marks the eastern terminus of Interstate 66. U.S. 29 continues as a freeway viaduct to the Francis Scott Key Bridge at Canal Road west / M Street east. Photo taken 08/04/13.
Interstate 66 West
Interstate 66 west begins along a flyover from U.S. 29 (Whitehurst Freeway) north across Rock Creek, Rock Creek Parkway and 27th Street NW. Substandard guide signs direct motorists to the two D.C. ramps of I-66 west: E Street Expressway east from the right and the Potomac River Freeway south to Ohio Drive on the left. Photo taken 08/04/13.
2 photos
2 photos
Two lanes merge from I Street NW as Interstate 66 passes through a cut and cover tunnel below the traffic circle between Virginia and New Hampshire Avenues. Photos taken 08/04/13.
Interstate 66 emerges from the tunnel and immediately partitions with the Potomac River Freeway south for the initial approach to the Theodore Roosevelt Memorial Bridge. The I-66 mainline includes access to E Street Expressway east into Foggy Bottom.
The sign bridge here includes covered panels for perhaps unconstructed Interstate 695 (South Leg Freeway) east to the Southwest Freeway (I-395). Photo taken 08/04/13.
A left side ramp quickly departs Interstate 66 west for E Street Expressway east to 20th and 17th Streets NW. All trucks are required to depart I-66 by this point, as they are prohibited from the freeway west to the Capital Beltway. Photo taken 08/04/13.
The lone reassurance marker for Interstate 66 was posted ahead of the merge with U.S. 50 west from Constitution Avenue NW. It was removed by 2007. Photo taken 01/20/00.
Interstate 66 U.S. 50 West
Interstate 66 & U.S. 50 west overlap for four miles across the Theodore Roosevelt Memorial Bridge. I-66 transitions into an all-HOV freeway through Arlington, Virginia. Photo taken 08/04/13.
A substandard and misleading sign indicates to drivers that the left lane is required to continue along Interstate 66. The Theodore Roosevelt Bridge accommodates seven overall lanes. Photo taken 08/04/13.
The right lane departs for both the continuation of U.S. 50 west onto Arlington Boulevard and George Washington Parkway north. Arlington Boulevard circles southward as an expressway to the Virginia 27 (Washington Boulevard) freeway along side Fort Myer. Photo taken 08/04/13.
A second sign advises travelers bound for Rosslyn to move to the left for I-66 west. Pedestrian walkways line both directions of the Theodore Roosevelt Bridge. Photo taken 08/04/13.
Interstate 66 curves northward as U.S. 50 west parts ways at the Little River. The unnumbered exit splits with access to George Washington Parkway north to Langley and the Capital Beltway and U.S. 50 west through Arlington. Photo taken 08/04/13.
Potomac River Freeway north
The Potomac River Freeway begins north from Ohio Drive and quickly splits with ramps for Interstate 66/U.S. 50 west across the Theodore Roosevelt Bridge and E Street Expressway east. This would have been the west end of I-695 (South Leg Freeway) had it been built. Photo taken 08/04/13.
An arch bridge carries U.S. 50 east to Constitution Avenue NW above Potomac River Freeway north. Photo taken 08/04/13.
Potomac River Freeway south
2 photos
2 photos
Stacked flyover ramps shuttle motorists between Interstate 66 and E Street Expressway above the Potomac River Freeway. Photos taken 08/04/13.
Subsequent arch overpasses carry I-66 east and U.S. 50 east beyond their split from the Theodore Roosevelt Memorial Bridge over the ending Potomac River Freeway south. Photo taken 08/04/13.
A U-turn ramp at the Potomac River Freeway end provides return access to northbound at the ramps for I-66/U.S. 50 west and E Street Expressway east. Continuing south otherwise yields options for Rock Creek Parkway north and Ohio Drive south to Independence Avenue east. Photo taken 08/04/13.

  1. Potomac River Freeway (I-66),

Photo Credits:

    01/20/00 by Jeff Royston. 08/04/13 by AARoads.

Connect with:
U.S. 29
U.S. 50
E Street Expressway

Page Updated 06-11-2014.