[Crawford]

Does Union Station (DC) have current capacity issues? They have a very large platform area, and very limited commuter rail. MARC and VRE don't really run that many trains. Is the issue more on the concourse side, which, yeah, doesn't seem particularly big?

Just looking at Wikipedia, they appear to have more tracks than any station in the Amtrak system. Grand Central has many times more, but obviously not Amtrak. Penn has fewer despite many times more traffic. Even discounting LIRR and NJT (which are more than 90% of Penn traffic) Amtrak alone at Penn has more than twice the traffic of Union Station.

Amtrak will double train service between NY and DC, so I guess the concourse on the DC end would need to be bigger. And trains will have somewhat higher capacity, so overall passenger counts will more than double. I take Acela between NY-DC once or twice a year, and haven't noticed any major crowding issues on the DC end, but it would be likely in the coming years.

And yeah, as others have mentioned, DC Union is kinda weird. The renovation was glorious, but it isn't really a train station. The tacked-on concourse is inadequate, and they should have renovated the original building to be a train station. Since the mall largely failed, you have this incredible space that is super-underutilized, and the obvious use is the original, intended use.