Interstate 66

Interstate 66 is the main east-west Interstate Highway in Northern Virginia. Upon entering Northern Virginia via the Theodore Roosevelt Memorial Bridge in Rosslyn, Interstate 66 runs 75 miles west to its ending point at Interstate 81 in Middletown, VA. Inside the Capital Beltway, I-66 serves Arlington County and the City of Falls Church . Beyond the Beltway, I-66 serves Vienna, Fairfax, Fair Lakes, Centreville, Manassas, Gainesville and Haymarket as well as further out towns like Marshall and Front Royal. Interstate 66 also provides a link in the westbound direction to the Dulles Airport Access Highway and the Dulles Toll Road. The Metrorail Orange Line runs in the median of I-66 from just west of Clarendon to the Orange Line terminus at the Vienna station which is located just past Nutley Street along I-66.

Interstate 66 is one of the most congested roads in Northern Virginia featuring miles long backups both during rush and non-rush hour times. To combat congestion, I-66 has one concurrent flow HOV-2 Lane (two or more persons per vehicle) running from the Capital Beltway to VA 234 Bypass in Manassas. During the HOV hours in the respective direction on I-66, the right shoulder is converted into a general purpose lane leaving no shoulder - only emergency turnouts - between the capital Beltway and US 50 in Fairfax. This has resulted in several high profile fatal accidents involving disabled vehicles being rear ended by others in the shoulder lane. Inside the Capital Beltway, ALL LANES of Interstate 66 inside the Capital Beltway are restricted to HOV-2 traffic during morning and afternoon rush hours. Traffic travelling to and from Dulles Airport is allowed inside the Beltway during HOV hours regardless of the number of occupants in the car. These significant HOV restrictions were a part of the compromise between Arlington County and the Virginia Department of Transportation that led to the construction of Interstate 66 inside the Capital Beltway. The table below shows the HOV hours for Interstate 66.

HOV-2 Restriction Hours for Interstate 66
Inbound (Eastbound)	Outbound (Westbound)
Outside the Capital Beltway (VA 234 Business to I-495)	5:30 AM - 9:30 AM	Inside the Capital Beltway (I-495 to the Roosevelt Bridge)	4:00 PM - 6:30 PM
Inside the Capital Beltway (I-495 to the Roosevelt Bridge)	6:30 AM - 9:00 AM	Outside the Capital Beltway (VA 234 Business to I-495)	3:00 PM - 7:00 PM

HOV Lanes on Interstate 66 are currently being extended to US 29 (Lee Highway) in Gainesville. This is the last of two projects to widen I-66 from Manassas to Gainesville. The US29/I-66 interchange will also be improved as a part of the HOV Lanes project. VDOT is also doing a comprehensive study of the Interstate 66 Cooridor to determine current and future transportation needs within the cooridor.

Interstate 66 has seen its share of controversy over the years. In the 60's and 70's, Arlington County residents and their government protested the construction of I-66 inside the Beltway. For a while, Arlington County had removed I-66 from its Master Plan of Highways. This controversy resulted in a largely scaled down I-66 inside the Beltway. The aforementioned HOV restrictions inside the Beltway were a part of this plan. Also, I-66 was to have a spur, I-266, that would have run from the current Spout Run Parkway exit across the Potomac River to a reconstructed Whitehurst Freeway. This road was cancelled during the DC Highway Revolt of the 70's.

The following two pages have excellent information on the history and construction of I-66, especially inside the Capital Beltway.

Exit Number	Route that Crosses I-66	Notes
1	I-81 Winchester/Roanoke - Westbound ONLY	Eastbound access is from Interstate 81.
6	US 340-522 Front Royal/Winchester	Eastbound traffic to Skyline Drive exit here.
13	VA 79 TO VA 55 Linden	Westbound traffic to Skyline Drive exit here.
18	VA 688 Markham
23	VA 729 TO VA 55 AND US 17 NORTH - Eastbound ONLY	No direct re-entry Eastbound at this interchange.
23	US 17 NORTH Winchester - Westbound ONLY	US 17 and VA 55 multiplex with I-66 at this point.
27	VA 721/VA 55/US 17 BUSINESS Marshall	End VA 55 Multiplex
28	US 17 SOUTH Warrenton/Fredericksburg US 17 BUSINESS Marshall	End US 17 Multiplex
31	VA 245 Great Meadow/The Plains
40	US 15 Warrenton/Haymarket	A little shortcut: Take US 15 SOUTH here to avoid traffic in Gainesville.
43	US 29 Gainesville/Warrenton (Signs going Eastbound mention Gainesville only.)	US 29 NORTH has no Control City listed on the Big Green Signs.
44	VA 234 SOUTH Prince William Parkway Manassas/Dumfries	The Manassas Bypass. Use VA 234 Business (Exit 47) to continue north Manassas on VA 234.
47	VA 234 NORTH Manassas Battlefield Park VA 234 BUSINESS (SOUTH) Manassas	End VA 234 Multiplex
52	US 29 Centreville
53	VA 28 Dulles Airport/Centreville
HOV Lane ONLY	VA 645 Stringfellow Road - Westbound ONLY	Left Exit. Open during HOV hours ONLY.
55	VA 7100 Fairfax County Parkway Reston/Herndon/Springfield
57	US 50 Fairfax/Winchester
HOV Lane ONLY	VA 6751 Monument Drive - Westbound ONLY	Left Exit. Open during HOV hours ONLY.
60	VA 123 Fairfax/Vienna
62	VA 243 Nutley Street Fairfax/Vienna	The "famous" Nutley Street where the big backups start going east or west during rush hour.
64	I-495 Capital Beltway Richmond/Baltimore
HOV Lane ONLY	I-495 Capital Beltway Richmond/Baltimore - Eastbound ONLY	Left Exit. Open at all times - restricted to HOV vehicles during HOV hours.
66	VA 7 Falls Church/Tysons Corner
67	VA 267 WEST TO I-495 NORTH Dulles Airport - Westbound ONLY	TO Dulles Access Highway
68-A	Westmoreland Street - Eastbound ONLY
68-B	US29-VA 237 Washington Boulevard/Lee Highway - Eastbound ONLY
69	Sycamore Street Falls Church - Westbound ONLY
71	VA 237-VA 120 Fairfax Drive/Glebe Road - Eastbound ONLY
71	VA 120 Glebe Road - Westbound ONLY
72	Spout Run Parkway - Eastbound ONLY
73	Rosslyn/Key Bridge
75	VA 110 South Pentagon/Alexandria