"Cuts right through the inner-city underground"
Interstate 395 in DC is a great artery to get from one side of DC to the other in a relatively short time. It barely gets congested in DC because most people just use the main streets, so you can rarely go wrong by getting on it. It splits to become the Southeastern Freeway to put you out at Pennsylvania Avenue; or if you take the other direction, New York Avenue. A part of it runs underground so you don't get to do much site seeing, but it was well designed to service a highly developed part of DC without destroying its landscape with overpasses.