"The old technology was light rail and the new technology Personal Rapid Transit, or PRT. Engineers at the U showed that PRT could do a superior job for about a third of the cost in energy and money compared to buses and trains, including "light" trains. It could do this because it involves very light electric vehicles carrying only one to three passengers on nonstop, one-way trips above existing transportation grids on 3-foot diameter guideways. They showed that PRT could operate 24 hours a day over entire areas rather than be confined to schedules on high-density corridors because it requires no drivers and that it could be built without tearing up neighborhoods or businesses for years. Per mile, it would cost about one-tenth as much to build as light rail.
These are not 'hard numbers' but careful estimates, because vested interests quickly got a provision written into law forbidding consideration of any technology not fully proven. Engineers and the U wanted to prove it.
But that requires permission from politicians, and 'light' rail was busy spending millions to prepare the political ground for their old streetcar technology. Some among them recognized the peril the new PRT represented to their selfish interests. They could not hold our region hostage to a system that requires vast annual subsidies to operate if the U's invention became well known. So they did all they could to strangle it in the crib."