Editing Interstate 66 (section)

==== Interstate 81 to Dunn Loring ====
[[File:2018-10-12 11 58 26 View west along Interstate 66 at Exit 1 (Interstate 81, Roanoke, Winchester) in northwestern Warren County, Virginia.jpg|thumb|Western terminus of I-66 at the interchange with [[Interstate 81 in Virginia|I-81]] in [[Middletown, Virginia]]]]
[[File:2018-10-23 12 24 56 View west along Interstate 66 and the Orange Line of the Washington Metro from the overpass for Virginia State Route 243 (Nutley Street) in Oakton, Fairfax County, Virginia.jpg|thumb|I-66 in [[Oakton, Virginia|Oakton]], with a [[Washington Metro]] train using the tracks in the median]]
I-66 begins at a [[directional T interchange]] with [[Interstate 81 in Virginia|I-81]] near [[Middletown, Virginia]]. It heads east as a four-lane freeway and meets [[U.S. Route 522|US&nbsp;522]]/[[U.S. Route 340|US&nbsp;340]] at a [[partial cloverleaf interchange]]. The two routes head south to [[Front Royal, Virginia|Front Royal]] and north to [[Lake Frederick, Virginia|Lake Frederick]]. I-66 continues east and crosses the [[Blue Ridge Mountains|Blue Ridge]] at [[Manassas Gap]], paralleling [[Virginia State Route 55|SR&nbsp;55]] (John Marshall Highway) and meeting [[U.S. Route 17 in Virginia|US&nbsp;17]] at a partial interchange with no access from southbound US&nbsp;17 to westbound I-66. SR&nbsp;55 also merges onto the freeway at this interchange, forming a three-way [[Concurrency (road)|concurrency]] that ends near [[Marshall, Virginia|Marshall]], with SR&nbsp;55 leaving along with [[U.S. Route 17 Business (Marshall, Virginia)|U.S. Route&nbsp;17 Business]] (US&nbsp;17 Bus.) and US&nbsp;17 leaving at the next exit. The freeway then passes through [[Bull Run Mountains|Bull Run Mountain]] at [[Thoroughfare Gap (Bull Run Mountain)|Thoroughfare Gap]].

Expanding to six lanes, and continuing to parallel SR&nbsp;55, I-66 enters the towns of [[Haymarket, Virginia|Haymarket]] and [[Gainesville, Virginia|Gainesville]], reaching interchanges with [[U.S. Route 15 in Virginia|US&nbsp;15]] (James Madison Highway) and [[U.S. Route 29 in Virginia|US&nbsp;29]] (Lee Highway) in each town, respectively. The highway then expands to ten lanes and heads to the south of [[Manassas National Battlefield Park]] and to the north of [[Bull Run Regional Park]]. The highway reaches another interchange with US&nbsp;29 and passes to the north of [[Centreville, Virginia|Centreville]] and meets [[Virginia State Route 28|SR&nbsp;28]] (Sully Road) at an interchange with cloverleaf and stack elements to it. SR&nbsp;28 heads north to [[Dulles International Airport]] and south to [[Manassas, Virginia|Manassas]].

The freeway then meets [[Virginia State Route 286|SR&nbsp;286]] ([[Fairfax County Parkway]]), [[U.S. Route 50 in Virginia|US&nbsp;50]] (Lee Jackson Memorial Highway), and [[Virginia State Route 123|SR&nbsp;123]] ([[Chain Bridge (Potomac River)|Chain Bridge]] Road) at a series of interchanges providing access to D.C. suburbs. The [[Orange Line (Washington Metro)|Orange Line]] and [[Silver Line (Washington Metro)|Silver Line]] of the [[Washington Metro]] begin to operate in the median here, as the highway reaches a large interchange with the [[Interstate 495 (Washington, D.C.)|I-495]] ([[Capital Beltway]]).

I-66 has two tolled [[High-occupancy toll lane|HOT lanes]] from US&nbsp;29 in Gainesville to the Capital Beltway.<ref>{{Cite web |last=Leayman |first=Emily |date=2022-11-29 |title=I-66 Express Lanes Open Ahead Of Schedule In Northern Virginia |url=https://patch.com/virginia/vienna/i-66-express-lanes-open-ahead-schedule-northern-virginia |access-date=2024-04-01 |website=Patch |language=en}}</ref>