As the articles on this site have pointed out time and time again, hovercraft are really the only logical choice for increasing mass transit in the D.C. Metro area.
Hovercraft are far less expensive than any of the currently available alternatives. The least expensive of the alternatives is 3 times as costly and the most expensive [...]

The first known concept for a vehicle that could be called a hovercraft was in 1716. This vehicle never made it past the concept stage since the designer, Swedish Emanuel Swedenborg, used a man powered, oar driven system for propulsion. Obviously, this idea just could not produce enough power to lift the craft.
In the 1870’s [...]