"The new report estimates that the light rail line would cost $411.3 million to $582.3 million in 2007 dollars, but generate $704.9 million in annual economic benefits, and yield $175.4 million a year in additional fiscal benefits to the city and state.
By speeding up crosstown travel time, the project would raise commercial property values by $1 billion - a result of ground-floor business revenue, rent and occupancy increases and reduction in accidents - and increase business in retail shops and restaurants by 35 percent, the study estimates.
The report notes that until 1946, streetcars and trolleys ran in New York City over underground utility lines. The new light rail cars could draw power from fuel cells or other advanced technologies. The trip from river to river would take only 21 minutes, even with speeds limited to 15 m.p.h. to keep pedestrians safe."