Interstate 66

Interstate 66
I-66 highlighted in red
Route information
Length	76.28 mi[1] (122.76 km)
Existed	1961–present
NHS	Entire route
Restrictions	No trucks on Custis Memorial Parkway or Theodore Roosevelt Bridge
Major junctions
West end	I-81 in Middletown, VA
Major intersections	US 340 / US 522 in Front Royal, VA US 17 / SR 55 in Delaplane, VA US 15 in Haymarket, VA US 29 in Centreville, VA SR 28 near Centreville, VA SR 286 near Fair Oaks, VA US 50 in Fair Oaks, VA I-495 in Dunn Loring, VA SR 267 in Idylwood, VA George Washington Parkway in Arlington, VA
East end	US 29 in Washington, D.C.
Location
Country	United States
States	Virginia, District of Columbia
Counties	VA: Frederick, Warren, Fauquier, Prince William, Fairfax, Arlington DC: City of Washington
Highway system
Interstate Highway System Main Auxiliary Suffixed Business Future
Virginia Routes Interstate US Primary Secondary Byways History HOT lanes
Streets and Highways of Washington, DC Interstate US DC State-Named Streets
← SR 65 VA → SR 67 ← US 50 DC → I-95

Interstate 66 (I-66) is a 76.32 mile east–west Interstate Highway in the eastern United States. The highway runs from an interchange with I-81 near Middletown, Virginia, on its western end to an interchange with U.S. Route 29 (US 29) in Washington, D.C., at the eastern terminus. Much of the route parallels US 29 or State Route 55 (SR 55) in Virginia. I-66 has no physical or historical connection to US 66, which was located in a different region of the United States.

The E Street Expressway is a spur from I-66 into the Foggy Bottom neighborhood of Washington, D.C.