Water taxis glide to Georgetown and Alexandria, VA (where you can transfer to another water taxi to reach National Harbor, MD). One-way fares start at adult/child $12/8.40; it’s a 25-minute ride.
Offers the most trips to NYC (around 15 to 20 per day), as well as other east-coast cities; arrives at/departs from Union Station. Buses run behind schedule fairly often.
Buses go to NYC multiple times each day, and to other east-coast cities. Lateness and spotty wi-fi can be issues. It uses Union Station as its terminal.
Travels throughout the northeastern US; has its terminal at Union Station.
Provides nationwide service. The terminal is at Union Station.