The Capital Beltway around Washington, DC
"Inside the Beltway" is an American idiom used to characterize matters of greater interest to U.S. federal government officials, contractors, lobbyists, and media personnel, than to their general public. The Capital Beltway (Interstate 495) is a highway that has encircled Washington, D.C. since 1964. Some speakers of American English now use "beltway" as a metonym for federal government insiders (cf. Beltway bandits).[1] Multiple political columns are titled after the phrase, including the Washington Times,[2] American University's magazine,[3] and columnist John McCaslin.
Geographically, Inside the Beltway describes Washington, D.C., and those sections of Maryland and Virginia that lie within the perimeter of the Capital Beltway.