During “the peak hour” of high speed commuter rail in the San Francisco Bay area, a train will pass through every three minutes. Neat, huh? Except – The rail line will cross 41 streets. Every three minutes, a train will bring traffic to a stop at 41 different places. That means “the number of vehicles that can cross the rail grade in gate up periods between trains during the peak will decrease by 60%. During peak hours, gate down times will approximately double.” And, the trains crossing city streets will be running at speeds up to 110 miles an hour.
The system is expected to cost only a little more than $100 billion. BILLION.
Link at http://ace.mu.nu/#370850