What is Beltway?
1.
Nickname for the highway (I-495) that encircles Washington DC through the surrounding states of Virginia and Maryland.
A defining feature of your DC-respective locale is whether it is inside or outside the beltway.
"Inside the beltway" can also refer generically to politics in the US capital city.
Person 1: I live in DC.
Person 2: No you don't. You live in Bethesda.
Person 1: Well, yeah, but it's inside the beltway.
Commuter 1: Traffic on the beltway sucked this morning.
Commuter 2: It always sucks. That's why I take the Metro.
See