| Interstate 66 in Virginia |
Interstate 66 in Virginia traverses 74.84 miles east-west from I-81 in Warren County to the District of Columbia border (Potomac River) in Arlington County. I-66 serves the towns and cities of Strasburg, Front Royal, Manassas, Fairfax, Vienna, Falls Church, Arlington, and the District of Columbia. I-66 was built near to and parallel to existing major interregional highways; VA-55 from I-81 to Gainesville, and US-29 from Gainesville to the District of Columbia. Virginia I-66 had one planned Interstate spur route, I-266, which was cancelled in 1977.
The terrain that Virginia I-66 crosses is generally Piedmont rolling land through the northern part of the state, from the Shenandoah Valley to the Nation's Capital. I-66 crosses two major transportation barriers, the Blue Ridge Mountains and the Potomac River.
I-66 crosses a variety of both rural areas and very urbanized areas. I-66 serves Northern Virginia, which is the regional name of the Virginia suburbs of D.C., with a population of almost 2 million people. I-66 crosses the Theodore Roosevelt Bridge over the Potomac River into D.C. and ends in several arterial branches in the western central business district. I-66 runs 77 miles from I-81 near Strasburg, Virginia, to 22nd and K Street, N.W. in the District of Columbia. The D.C. terminus also includes high-capacity connections to Constitution Avenue, N.W. and E Street, N.W.
Route openings. The first section of I-66 to open to traffic was on Dec. 16, 1961 with the 8.6-mile-long section from US-29 at Gainesville to US-29 at Centreville. The 12.9-mile-long section from Centreville to I-495 opened in November 1964, completing the 21.5-mile-long highway from Gainesville to I-495, and providing a direct connection to 4-lane divided US-29 from Gainesville to Warrenton. An isolated 3.3-mile-long section of I-66 near Delaplane in Fauquier County was opened in May 1962. The Theodore Roosevelt Bridge opened on June 23, 1964, and an 0.2 mile extension section to Rosslyn opened in Oct. 1966. The 6.6-mile-long section of I-66 from I-81 to US-340/US-522 north of Front Royal opened in Oct. 1971. The 15.6-mile-long section from US-340 to I-66 at Delaplane was completed in August 1979. The 2.9 miles from I-66 at Delaplane to US-17 east of Marshall was completed in 2 sections in 1978 and 1979. The 11.7 miles from US-17 at Marshall to US-15 at Haymarket opened in Dec. 1979, and the final 3.1 mile I-66 rural link from US-15 to I-66 and US-29 at Gainesville opened Dec. 19, 1980. The final section of I-66 to be completed was the 9.61-mile-long urban expressway from I-495 to US-29 at Rosslyn, and that opened on Dec. 22, 1982, completing I-66.
Traffic volumes on I-66 vary widely. VDOT 1997 traffic volume data follows. Figures are published rounded to the nearest 100. The 13 miles from I-81 at Strasburg to VA-79 at Linden carries from 18,100 to 19,600 annual average daily traffic (AADT) with 14% large trucks. The 15 miles from VA-79 at Linden to US-17 east of Marshall carries 26,000 to 34,000 AADT with 20% large trucks. The 15 miles from US-17 east of Marshall to US-29 at Gainesville carries 28,000 AADT with 20% large trucks. Traffic from US-29 at Gainesville to VA-234 is 56,000 with 20% large trucks, and increases to 70,000 just east of Bus. VA-234; 89,000 just east of US-29 at Centreville; 131,000 just east of VA-28; 141,000 just east of VA-7100; 162,000 just east of US-50; and 202,000 from VA-243 Nutley Street to I-495; with large trucks averaging around 9% from US-29 at Gainesville to I-495. AADT just east of VA-267 Dulles Airport Access Road is 98,000; and is 102,000 at VA-120 Glebe Road, and the entire 9.6-mile-long section from I-495 to US-29 at Rosslyn by law carries no large trucks. The Theodore Roosevelt Bridge carries 98,000 AADT with 9% large trucks.
Number of lanes. These sections of I-66 were initially built with 6 lanes: The 7 miles from US-50 to I-495, and the 1.5 miles from Rosslyn to the terminus in D.C. The remainder was built with 4 lanes.
In 2000, I-66 in Virginia has 8 lanes for 17 miles from just west of VA-234 near Manassas to I-495 near Vienna. I-66 also carries the WMATA Metrorail rapid rail transit line and 4 stations in the highway median for 10 miles from just west of Nutley Street near the city of Fairfax, to Fairfax Drive in Arlington.
Major Interstate widening projects on I-66 include: Widened 18 miles from VA-234 to I-495 (from 4 and 6 lanes, to 8 lanes, 1997).
New interchanges added to the original I-66 are: In Prince William County, VA-234 Manassas Bypass, 1998. In Fairfax County, VA-7100 Jack Herrity Parkway (Fairfax County Parkway, 1994.
I have detailed information about I-66 here: Interstate 66 and Metrorail Vienna Route