Interstate 66

Interstate 66 marker
Interstate 66
Map
I-66 highlighted in red
Route information
Length76.28 mi[1] (122.76 km)
Existed1961–present
NHSEntire route
RestrictionsNo trucks on Custis Memorial Parkway or Theodore Roosevelt Bridge
Major junctions
West end I-81 in Middletown, VA
Major intersections
East end US 29 in Washington, D.C.
Location
CountryUnited States
StatesVirginia, District of Columbia
CountiesVA: Frederick, Warren, Fauquier, Prince William, Fairfax, Arlington
DC: City of Washington
Highway system
SR 65VA SR 67
US 50DC 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. 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 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.

  1. ^ "Table 1: Main Routes of the Dwight D. Eisenhower National System of Interstate and Defense Highways as of October 31, 2002". Route Log and Finder List. Federal Highway Administration. Archived from the original on September 8, 2012.