To go from 0 to 220 mph is like going from kindergarten to graduate school in one step. It's why every high-speed rail system built in the world has had a conventional-speed precedent.
To bring this discussion back to its topic, a light-rail system can be part of that support network for a high-speed rail line.
True. I'd much rather see 220 MPH high-speed rail than conventional 79 MPH, and I'd much rather see a fully grade-separated heavy rail metro system than surface-running light rail. But conventional passenger rail and light rail are positive steps in the right direction. In the future, if ridership warrants (and I'm confident it eventually will), conventional intercity rail can be upgraded to high-speed rail, and light rail can be upgraded to heavy rail. I just hope that the rail systems being proposed today are built in a manner so that future upgrades can be achieved with a minimum of headaches.
