How about I start by pointing out something less than obvious. Regulation on existing legacy systems makes it hard for innovation on current technologies.
High Speed Rail in Europe and Asia was looked at and modified to fit into existing US models with Amtrak’s Metroliner. At the end of the day the “high speed” it hits is only between Providence Rhode Island and South Street Station, Boston. It’s not Amtrak’s fault, but it shows that legacy often thwarts innovation.
Elon Musk, has support from the Trump Administration, the governor of Maryland and the mayor of Washington DC for his Hyperloop rail service from his company Boring. The Boring Company has also been granted a permit, according to the Washington Post, by D.C. Mayor Muriel E. Bowser to start a tunnel at NY Avenue at a vacant lot next to McDonalds. When looked at with the Maryland approval of a 10.1 route to Baltimore following Maryland 295 you can see a few valuable ideas.
The first is revitalization. New York Avenue is the entrance into the city from 295 and the most direct route driving to the Capital from the Northeast. If you have driven the route as often as I have you know exactly where that McDonald’s is located. If you have not driven that route, the opening credits of NCIS has a scene looking at the capital from NY Ave. Regardless, while the area is convenient it has looked pretty shoddy for a longtime and a high speed commuter system would revitalize the area tremendously.
Direct routes are better. As the Boring Company website points out the trick is to find two end points you want to connect and keep as close to a straight line as possible. This Parkway is the most direct route, but has lots of potential traffic problems with stadiums nearby and large corporate campuses having direct exits. A tunnel would bypass this traffic and deliver downtown to downtown.
The last is synergies. Ignoring the Boring Company would be needed for Elon’s vision to populate Mars. His consortium of companies developing Electric vehicles, energy solutions, and rocket propulsion and tunneling is a cohesive vision. While we hear lots of smart city strategies, Elon Musk has plans for a smarter world.