California's High-Speed Rail Authority gauged private sector interest in the $43 billion project with a recent conference that brought contractors and investors out in force. "The real high-speed rail systems in the world generate cash," said rail authority CEO Roelof van Ark. Meanwhile, a debate is heating up over whether to elevate high-speed rail through the Palo Alto area or run high-speed trains over current Caltrain tracks. Some residents in the region are opposed to construction of an above-ground bullet train. Supporters say the train would have to be elevated to achieve "bullet" speeds.