From LA TIMES: The bullet train will require about 20 miles of tunnels under the San Gabriel Mountains between Burbank and Palmdale, involving either a single tunnel of 13.8 miles or a series of shorter tunnels. As many as 16 additional miles of tunnels would stretch under the Tehachapi Mountains from Palmdale to Bakersfield. The state will probably opt for twin bores — one for each of two parallel tracks. That means as many as 72 miles of tunneling before 2022.
Can it meet that schedule?
"No way," said Leon Silver, a Caltech geologist and a leading expert on the San Gabriel Mountains. "The range is far more complex than anything those people know."
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