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. "No way," said Leon Silver, a Caltech geologist and a leading expert on the San Gabriel Mountains.
The authority owns only a small fraction of the parcels it needs for the 300-mile segment from Burbank to Merced.
Above, a property on Wentworth Street in Tujunga, where a tunnel may be dug in the San Gabriels.
"Once cost increases start, they are likely to continue."Flyvbjerg's research found that high-speed rail projects around the world experience an average of 45% cost growth, though 100% increases occur in some cases.
Although the state hopes to correct some of its early setbacks, the odds are stacked high against it, said Robert Bea, a member of the National Academy of Engineering and a pioneer in civil engineering risk analysis."You can never make up an early cost increase," Bea said. I have never seen it go the other way in 60 years."Of the challenges facing the bullet train, none is bigger than tunneling.
And it projected that the cost of the entire project would rise at least 5%.