The planned high speed rail line linking Sacramento, San Francisco, Los Angeles and points south is nonsense. You can have the rail line but it won’t be high speed because of engineering problems. The engineering problem is called the Tehachapi Mountains. Interstate 5 is the main inland road from Los Angeles to points north. It crosses the Tehachapi Mountains just north of Los Angeles at a town called Castaic. Where it crosses the Tehachapis it is 4 or 5 lanes in each direction to allow what must, for safety and engineering reasons, be very slow moving trucks. The truck speed limit for much of the Tejon pass (aka the Grapevine which is the part of I-5 that crosses the Tehachapis) is 35 miles per hour. Going uphill, most big rigs do not have the muscle power to go much faster than that. Going downhill, they are restricted to that speed to prevent runaway trucks, which still plague this highway. For those not aware a runaway truck is one in which the brakes aren’t working any more and gravity is increasing the speed. Runaway trucks threaten death not only to the driver but anyone in their path.
The grade on either side of the pass for autos and trucks exceeds 6%. The highest elevation of the pass itself (much lower than the surrounding mountains) is over 4,000 feet.
There is no need to debate whether a train can be constructed that can cross these mountains. One was constructed in the late 1800’s and is in use to this day. The Tehachapi Loop, constructed by Southern Pacific, is still considered an engineering marvel. It is constructed so that the maxium grade on the pass is 2.2%. At the Tehachapi loop, long trains actual pass over themselves.The speed limit through the loop is 23 miles per hour. Which fact is probably the reason that Amtrak rarely sends passenger trains over the rails. Instead, when you take an Amtrak train from Sacramento to Los Angeles, you get off the train in Bakersfield, get on a bus, and then get off the bus and get back on the train in San Fernando. I’m not kidding. And all of this is faster than actually routing the train over the Tehachapi pass.
I am told by someone who knows in the California Department of Transportation (aka CalTrans) that the plan for a high speed train is to dig a tunnel under the Tehachapi mountains. Obviously, such a tunnel is possible. There is, after all, a tunnel under the English channel. The cost of the Chunnel is estimated to have been $15 Billion dollars. That was in the 80s so double that for 21st century dollars. Another problem for builders is that any route in the Tehachapis is in a seismically active area. Any train travelling from north to South will have to cross the San Andreas fault. The San Andreas fault is a very seismically active faults and the Tejon pass is one of the most seismically active areas– meaning in plain English, movement along that fault and intersecting faults has caused a lot of big earthquakes.
So, how really practical is it to dig this tunnel and run a train through it? You can already fly round trip from Southern California to Sacramento or San Francisco for between $100 and $250 dollars. What this project really is, is an enormous boondoggle in which favored contractors will be paid billions of dollars to conduct studies without ever actually building the tunnel or the rail line. It is a complete waste of money and should be stopped.