Interstate 495 (I-495): Driving on the Capital Beltway

What You Should Know Before Driving Around Washington DC

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••• Photo © Brendan Smialowski/Getty Images

Interstate 495 (I-495), also known as the Capital Beltway, is a 64-mile highway that encircles Washington, DC. The highway passes through Prince George's County and Montgomery County in Maryland, and Fairfax County and the City of Alexandria in Virginia. The two directions of travel, clockwise and counterclockwise, are known as the "Inner Loop" and the "Outer Loop". Access to Washington DC is provided by I-270 and I-95 from the north, I-95 and I-295 from the south, I-66 from the west, and US 50 from both the west and the east.

The most scenic routes from I-495 into Washington DC are offered by the George Washington Memorial Parkway along the Virginia side of the Potomac River, the Clara Barton Parkway along the Maryland side of the river, and the Baltimore-Washington Parkway, approaching downtown from the northeast.

See a Map and Guide to the Exits on the Capital Beltway

History of I-495

Construction of the Capital Beltway began in 1955. It was part of Interstate Highway System that was created in the Federal Aid Highway Act of 1956. The first section of the highway opened on in 1961 and it was completed in 1964. Originally I-95 was planned to serve downtown Washington, DC from the south and north, intersecting the Beltway in Virginia and in Maryland. However, the plan was canceled in 1977 and the built portion of I-95 inside the Beltway from the south running north into downtown Washington was redesignated as I-395.

Around 1990, the eastern side of the Beltway was dual-signed I-95-495. Exits were renumbered based on mileage from I-95's entry into Maryland at the Woodrow Wilson Bridge.

Traffic Congestion on I-495

The explosive growth of housing and business in the Maryland and Virginia suburbs has created heavy traffic around the region, especially on the Capital Beltway.

Despite numerous widening projects over the past few decades, heavy traffic is a continuing problem. Intersections on the Capital Beltway that are ranked as the "worst bottlenecks in the nation" are the interchange at I-495 and I-270 in Montgomery County, Maryland, the interchange at I-495 and I-95 in Prince George's County, Maryland and the Springfield Interchange, where I-395, I-95, and I-495 meet. Many organizations provide traffic reports that provide real-time information on the conditions on the roads including details on accidents, road construction, chemical spills, weather, and more. A wide range of transportation alternatives are available for commuters. Read more about commuting to Washington DC.

Interstate Driving Tips

  • Plan your route in advance and be sure to give yourself plenty of time to merge when exiting. In heavy traffic, it can be difficult to switch lanes and may require more time than you would expect.
  • Traffic can be unpredictable. Be flexible and ready to use an alternate route if necessary.
  • Avoid traffic congestion by traveling during non-rush hour periods. Washington DC rush hour is generally from 6-9 a.m. and 4-7 p.m. Monday through Friday.
  • Expect backups during rush hour at the Woodrow Wilson Bridge and the American Legion Bridge. At Route 123 and I-495 in Virginia, construction of the HOT lanes is causing delays at all times of the day.

    Virginia Hot Lanes on I-495

    The Virginia Department of Transportation opened high-occupancy toll (HOT) lanes in Northern Virginia in 2012. The project added two lanes to I-495 in each direction from just west of the Springfield Interchange to just north of the Dulles Toll Road, and included the replacement of more than 50 bridges, overpasses, and major interchanges. Drivers of vehicles with fewer than three occupants are required to pay a toll to use the lanes. An E-Z Pass transponder is required to allow for electronic toll collection. Tolls are waived for buses, carpools of at least three people, motorcycles, and emergency vehicles. 

    To learn more about driving in the area, see an Overview of Roads and Highways in the Washington DC Area.