Washington County, Maryland is included in the Hagerstown-Martinsburg, MD-WV Metropolitan Statistical Area, which is also included in the Washington-Baltimore-Arlington, DC-MD-VA-WV-PA Combined Statistical Area. The closes states to Washington County is west Virginia, Pennsylvania, Virginia, and Tennessee. The western portions of the Province of Maryland (including present Washington County) were incorporated into Prince George's County in 1696. This original county included six current counties. The first to be created was Frederick, separated from Prince George's County in 1748. Following independence, the sovereign State of Maryland formed Washington County on September 6, 1776, by the division of Frederick County. At the same time, a portion
Streets and highways of Washington, D.C. frequently used to describe the inside lanes of 495—that is, those that travel clockwise around Washington. A convergence indexing based road traffic monitoring system was installed on Washington's highways in 2008. The Anacostia Freeway (DC-295) continues in a northeasterly direction from the point where I-295 ends at its intersection with I-695 near the 11th Street Bridges on the south side of the Anacostia River and links with the Baltimore–Washington Parkway, which eventually becomes Maryland Route 295, via a short section of Maryland Route 201. The Suitland Parkway connects the city with the southeastern suburbs in Prince George's County, Maryland. The