Originally Posted by
Indelaware
Amtrak does not serve DCA, closest is Union Station. UA would still need to provide ground transport - for at least some pax - from Union Station to DCA. Moreover, EWR-Washington is not a code-share route.
Obviously, the train line doesn't connect to DCA, but Amtrak is a much more convenient option that a bus. And certainly the option I would have booked myself on. I actually can't believe there were passengers that chose to take the bus!