Interstate 495 (Capital Beltway)

Interstate 495 (Capital Beltway)
State	MD
State1	VA
Route	495
Alternate name	Capital Beltway
Length mi	64
Length km	103
Direction a	West
Direction b	East
Terminus a	Interstate 95 in Springfield, Virginia
Junction	Interstate 66 in Dunn Loring, Virginia, Interstate 395 in Springfield, Virginia, Interstate 95 in College Park, Maryland, Interstate 270 in Bethesda, Maryland
Terminus b	Interstate 95 in College Park, Maryland
Counties	Fairfax (VA), Alexandria (VA), Prince George's (MD), Montgomery (MD)
System	Interstate Highway System

Interstate 495 (Capital Beltway) is a 64-mile (103 km) auxiliary Interstate Highway that encircles Washington, D.C., passing through portions of the U.S. states of Maryland and Virginia. Commonly referred to as the Capital Beltway or simply the Beltway, it forms a vital loop around the Washington metropolitan area, connecting its major suburbs and serving as a critical conduit for regional and through traffic. The highway is one of the most heavily traveled roadways in the United States and has become a cultural and political symbol for the federal government and its surrounding communities.

Route description

The route begins at a complex interchange with Interstate 95 and Interstate 395 in Springfield, Virginia, proceeding clockwise. The southern portion in Virginia traverses Fairfax County and the independent Alexandria, passing near landmarks like Fort Belvoir and Mount Vernon. It crosses the Potomac River on the Woodrow Wilson Bridge into Maryland. The eastern and northern arc runs through Prince George's and Montgomery counties, skirting communities such as Oxon Hill, College Park, Silver Spring, and Bethesda, before crossing the American Legion Memorial Bridge back into Virginia. The highway provides direct access to key facilities including Tysons Corner, Pentagon, Andrews Air Force Base, and the National Institutes of Health.

History

Planning for a circumferential highway around Washington, D.C. began in the early 1950s by the Bureau of Public Roads. Construction commenced in the late 1950s, with the first section opening in Virginia in 1961 and the final segment in Maryland completed in 1964. The original Woodrow Wilson Bridge, a drawbridge, opened in 1961 and became a notorious bottleneck. Its replacement, a modern fixed-span bridge, was constructed in the 2000s and fully opened in 2008. The Beltway's completion catalyzed suburban growth in Fairfax County and Montgomery County, fundamentally shaping the development of the Washington metropolitan area.

Major junctions

Key interchanges include its termini with Interstate 95 in both Springfield, Virginia and College Park, Maryland. Major junctions clockwise include Interstate 395 and Interstate 66 in Virginia, the Woodrow Wilson Bridge, Maryland Route 5 and Maryland Route 4 in Prince George's County, Interstate 95 and Interstate 295 near College Park, U.S. Route 29 in Silver Spring, Interstate 270 in Bethesda, and the American Legion Memorial Bridge crossing back into Virginia.

Tolls and express lanes

The mainline Capital Beltway is a toll-free facility, except for the Woodrow Wilson Bridge. However, high-occupancy toll (HOT) express lanes operate along the Virginia portion of the Beltway. These 495 Express Lanes, developed through a public-private partnership with Transurban, run alongside Interstate 495 from the Springfield Interchange to just north of the Dulles Toll Road interchange. These lanes use dynamic tolling and require an E-ZPass for payment.

Traffic and incidents

The Beltway is perennially among the most congested highways in the United States, with average daily traffic volumes often exceeding 200,000 vehicles. Notable incidents causing major gridlock have included the January 1982 Air Florida Flight 90 crash aftermath, multiple hazardous material spills, and severe weather events. The highway is a focal point for regional traffic reporting by outlets like WTOP and is routinely monitored by the Virginia Department of Transportation and Maryland Department of Transportation.

Exit list

The exit numbering sequence runs clockwise from the Springfield Interchange (Exit 1/1A-B in Virginia) to the interchange with Interstate 95 in College Park, Maryland (Exit 27 in Maryland). Significant exits include those for Interstate 66 (Exit 49), Dulles Toll Road (Exit 45), U.S. Route 50 (Exits 7B-A in MD, 177 in VA), Baltimore–Washington Parkway (Exit 17), and Interstate 270 (Exit 34). The Maryland section uses a separate numbering sequence from the Virginia section.

Category:Interstate Highways in Maryland Category:Interstate Highways in Virginia Category:Transportation in Washington, D.C. Category:Circumferential highways in the United States