It took 22 years and almost $7B to build 22 miles of MRT (not high-speed rail) just outside of the DC beltway, and much of the route had an existing right-of-wa

It took 22 years and almost $7B to build 22 miles of MRT (not high-speed rail) just outside of the DC beltway, and much of the route had an existing right-of-way. It's a populous area, but the DC to Boston route is quite heavily developed.