what is capital beltway
Photo Â© 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.nterstate 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.