Put a fork in the idea of saving a few billions of dollars on California High-Speed Rail by switching from the Palmdale alignment to the I-5 alignment through the Grapevine. The HSR Authority conducted a new study and found that, after fiddling with the parameters to create the maximally bad result for the Grapevine alignment, the Grapevine alignment does not save money. Go to page 39-40 to see how convoluted the studied Grapevine option is. This is driven not by geotechnical considerations, but by political ones: the owners of Tejon Ranch, which covers much of the area of study, oppose HSR through their property. Even so, the base cost of the Grapevine is $13.5 billion, versus $15 billion for Palmdale; this difference was papered over by fudging a risk adjustment factor. As commenter Jon explains,
Having skimmed through the study, a few points come to mind:
1) The length of the I-5 route has increased largely due to the requirement to diverge from the current route east of Bakersfield rather than bypass Bakersfield to the west. I’m sure this requirement is driven by a desire to get the Frseno – Bakersfield EIR/EIS certified in time to start construction on the ICS. What would the effect of a west Bakersfield bypass be on the cost and travel time of an I-5 route?
2) The cheapest and fastest I-5 route bisected the proposed Tejon Ranch, but the study didn’t take this route forward to detailed analysis. Instead they analyzed a ‘considerably more expensive and slower’ route which cuts right through Lebec, in order to avoid the ‘significant cost and schedule risk’ involved in bisecting the Tejon Ranch. How fast and expensive would the I-5 route through the Tejon Ranch have been? How difficult would it be to permit this route?
3) Also the risk adjustment to account for the 5% design- this seems to be an obvious fudge. You can see everything they changed in Appendix B. What is the justification for increasing the risk allocation for real estate from 20% to 40%, for example?
Despite the potentially large cost difference, the HSR Authority is loathe to use eminent domain, even when the cost is much smaller than the alternative. Something similar happened in the Central Valley, when the initial plan to hew to existing transportation corridors became untenable as it became clear it would require many viaducts and grade separations, and only after value engineering has the cost overrun been limited by running around unserved cities. With a less positive result, it’s happened repeatedly on the Peninsula, for example with the substandard San Bruno grade separation project.
The problem here is that no value engineering is possible unless the I-5 option is kept open. Thus it’s important for us as good transit activists to demand that the HSR Authority engineer both options to learn more about the risk, allowing eventually for the cheapest and most reliable option to be picked.