As other have said, the Washington Metro is quite rollerbag-friendly. That is, as long as at least one elevator or set of escalators is operating. If the escalators aren't operating., there is at least one elevator (or set of elevators) that will get you from the platform to the street. There are times when a station might have no functioning elevators or escalators, but they will post that fairly prominently and describe alternate bus shuttles from stations where the elevators and escalators are working.Tourist question here. Are the Washington DC metro cars anywhere at all conducive to travelers to/from Union Station lugging a couple rollaboards? Most “subway” cars I’m familiar with elsewhere have barely any open floor space at all that would make that even remotely easy. Much less a space specifically for luggage while on board.
I should also inquire about how the station “toll gates” work for an old guy like me trying to pass through one dragging a suitcase behind me. Is using the Metro at all with luggage just a dumb idea?
One other note about Union Station: The underground entrance to Union Station at the southwest end from the mezzanine to the food court, involves about 3-4 steps. I can usually bump a rollerbag up or down this, but if you want to avoid that, just ride the regular escalators to the street level, and enter the station there. I think the elevator is at the northeast end of the platform, which exits to the train concourse.