Below is a guest post from Clem Tillier, who also writes the Caltrain-HSR Compatibility Blog
If you try to reach Los Angeles from the Central Valley and points north, the Tehachapi Mountains stand squarely in the way. This mountain range, crisscrossed by earthquake faults, forms a great barrier to California’s high-speed rail network and will (by geological and topographical necessity) result in one of the highest-elevation high-speed rail mountain crossings anywhere in the world. Reaching even the lowest passes requires a roughly 1000 m (3300 ft) vertical climb from the floor of the Central Valley, with sustained steep grades and tunnels and bridges of considerable length. The Tehachapi mountain crossing will surely be the most spectacular, complex and expensive section of California’s nascent high-speed rail backbone.
Crossing the Tehachapis is feasible at several topographically favorable locations, among which are Tehachapi Pass (to serve Palmdale and the Antelope Valley, as selected by the California High-Speed Rail Authority) and Tejon Pass, also known as the “Grapevine” or I-5 alignment. Two possible HSR alignments through these passes are shown in the map at right. The map, oriented such that the SF-LA axis is vertical, highlights one of the basic trade-offs of California high-speed rail: detour through the fast-growing but geographically isolated Antelope Valley, or take the direct shortcut to Los Angeles.
This trade-off was never technical. For political reasons that will not be discussed here, Tejon Pass was never seriously considered for high-speed rail.
During Roelof van Ark’s brief stint as CEO of the rail authority, staff and consultants were directed to reconsider the options and produced the Conceptual I-5 Corridor Study, published at the January 2012 board meeting–the same meeting where van Ark resigned his post. This study was tailored, rather blatantly as we will see, to reconfirm the route via Palmdale. The technical rationale for dismissing Tejon Pass alignments was built on numerous contrived assumptions and constraints that warrant close examination. A sophisticated path optimization tool, known as Quantm, was used to evaluate thousands of possible alignments through the Tehachapi Mountains, giving the false impression that they had been exhaustively researched; however, the tool was carefully tweaked to avoid some of the most promising alternatives. While thousands of alignments may have been considered, the hundreds that weren’t are far more interesting.
A Good Tejon Pass Alignment
The map below shows a reasonable Tejon Pass HSR alignment, by no means the best, in comparison to the probable Antelope Valley alignment. This map serves as a key to the rest of this article, and is even more revealing after downloading the KML file and opening it in Google Earth, where many of the locations, landmarks and topographical features discussed below are easily visualized in 3D.
View Larger Map
Myths About Crossing the Tehachapi Mountains
Twelve myths have developed around the complex issue of the HSR southern mountain crossing, and are often trotted out to support the Antelope Valley alignment via Palmdale. These myths, all of them wrong, include the following:
- Tejon Pass HSR alignments cannot cross into Tejon Mountain Village property
- Tejon Pass HSR requires more tunneling than the Antelope Valley
- Tehachapi Pass is the easier mountain crossing, as the Southern Pacific Railroad figured out way back in the 1870s
- Tejon Pass HSR suffers from greater seismic risk, compared to Antelope Valley HSR
- Tejon Pass HSR via Santa Clarita would significantly impact Newhall Ranch
- Antelope Valley HSR via Tehachapi Pass alignment can just plug into the electric grid
- Bakersfield can be crossed at 220 mph
- Bakersfield must be served with a downtown station
- Tejon Pass HSR is only 3-5 minutes faster than Antelope Valley HSR
- HSR can operate at 220 mph on long and steep down grades
- Tejon Pass HSR costs about the same as Antelope Valley HSR
- Tejon Pass HSR screws Palmdale. Palmdale will never get a fast rail connection to LA unless it is on the HSR main line
A blog post is the wrong medium to address such complex issues; instead, the following presentation dismantles each of the myths using numerous figures and diagrams to illustrate each point. These 75 slides are also available for download, 7MB PDF in much better resolution than provided by Scribd.
The conclusions are stunning. Compared to the Antelope Valley alignment currently being planned with a stop in Palmdale, the more direct Tejon Pass HSR alignment would have the following advantages:
- 12 minutes faster (7% of the SF – LA trip time)
- 34 miles shorter
- 10+ fewer miles of tunnel
- 20 fewer miles of bridges
- $5 billion cheaper to build
- $175 million/year more profitable to operate
You might ask yourself at this point how some guy on the internet can come up with this stuff and claim that it undercuts years of studies by professional consultant teams paid hundreds of millions of dollars. The point is that when it comes to math and physics, the numbers don’t lie. The numerous advantages of a Tejon Pass alignment will not be lost on potential private investors, who will spare no effort to produce their own untainted investment-grade analysis of the mountain crossing. If their numbers turn out anywhere close to this (and they will!) there simply won’t ever be any private investment.
Considering that the 2012 business plan relies on $13 billion of private capital (about 20% of the $68 billion overall budget), choosing the wrong mountain crossing could make or break HSR in California. If the numbers presented here are to be believed, the smart money will demand a Tejon Pass alignment. Failing this, private capital will stay away, and California’s high-speed rail system is unlikely to be completed as planned.
That’s why smart HSR supporters, those who are analytically-minded and open to new information, should place their full support behind the re-alignment of California’s high-speed rail backbone via Tejon Pass.