Interstate 66

Interstate 66
Interstate 66
	I-66 highlighted in red
Route information
Length	76.28 mi (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 near Middletown, VA
	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;

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. The route parallels State Route 55 (SR 55) from its western terminus at I-81 to Gainesville, and US 29 from Gainesville to its eastern terminus in Washington. I-66 is unrelated to US 66, which was located in the Midwest-West region of the United States.

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