California HSR’s just-released July progress report, as reported on bakersfield.com, contains the pleasant surprise that switching the alignment from the Tehachapis and Palmdale to the I-5 alignment on the Grapevine could save $4 billion.

Furthermore, the study indicating such cost savings “identified more than one feasible alignment over the mountain pass.” The Grapevine option was rejected in 2005 because the preliminary engineering found only one feasible alignment that crosses known faults at-grade and has a maximum tunnel length of 6 miles and maximum 3.5% grade, compared with hundreds through the Tehachapis. Therefore finding multiple alignments, such that even if further meter-scale geological studies discover new faults then some option will make it through, is likely to tilt the field back toward the Grapevine.

Robert Cruickshank is surprisingly pessimistic about the Grapevine, on the grounds that Palmdale is an important market to serve. In reality, Palmdale is a small commuter market – i.e. it has a strong peak and low revenue per rider – so giving it up is a small deal, probably fully canceled out by the gain of about 10 minutes’ trip time on the shorter Grapevine.

But most importantly, it’s most important to get an initial operable segment ready, and this means connecting the Central Valley to the LA Basin. As I’ve explained before, a major advantage of the Grapevine is that it allows connecting to the legacy Metrolink line at Santa Clarita rather than at Palmdale, avoiding tens of kilometers of sharp curves on the climb between the LA Basin and Antelope Valley.

I’m unable to find the progress report, so I don’t know to what extent “$4 billion in savings” literally means coming in $4 billion under budget. If it does, it means that theoretically, the money available suffices to build from Los Angeles to a point between Bakersfield and Fresno; Obama’s now-moribund $4 billion for HSR, matched 50:50, would be more than enough to build from Los Angeles to Fresno.

Update: here is the progress report. The relevant section is on page 27. It says only that “an alternative via the Grapevine may save between $1B and $4B in capital cost” – still unclear whether it means coming $1-4 billion under budget, or staying within budget while avoiding a $1-4 billion cost overrun on the Tehachapis.

It’s too bad the approximate amount remains unclear. The required budget is on the same order as the amount that may become available in the next two years depending on Congressional machinations, and so it’s important for California to know how much it should be asking for. For example, if it were made clear that an additional $2.5 billion in federal funding were enough to complete LA-Fresno, then Dianne Feinstein might try to include the full amount for high-speed rail in the transportation bill for 2012 rather than just $100 million.

California is going ahead with construction of the Central Valley segment, and has just publicly released an email saying it will solicit bids in 3 months, totaling about $6 billion from Bakersfield to just south of Merced, a distance of about 200-210 kilometers. The alignment bypasses some small towns but not all, avoiding some of the scope creep that happened in the years leading up to the Business Plan, which required more elevated segments; however, some towns will still require many grade separations and viaducts, and so will Fresno and Bakersfield.

The HSR Authority has just released environmental impact reports for the Bakersfield-Fresno and Fresno-Merced that point out to higher costs: the sum of the two cheapest alternatives is $10 billion, in 2010 dollars, for 300 km; although the cost per km is not much higher, the Fresno-Bakersfield segment is much more expensive, whereas the extra bits included in the EIR but not the bid request are the cheapest.

There is some additional room for value engineering, especially in Fresno, where the currently preferred alternative calls for viaducts, but the potential for cost saving is not that great, especially relative to the $6 billion estimate; projects run over budget much more frequently than they come under. The main interest here is not the cost overrun: the current stage, the bidding, is the one most prone to overruns, and no matter what, we will know in three months what the projected cost is. The interest is the breakdown of costs, which, as expected, are primarily infrastructure and tracks, including grading and grade separations. The cost overruns come from scope creep, with more elevated segments than originally expected (but, due to value engineering, less than expected in 2009).

At any case, there is money to proceed, at least from Bakersfield to Fresno – there is $6.3 billion available, half from federal spending (which has been spared in the latest austerity plan) and half from Proposition 1A’s matching funds. There is another almost $6 billion locked in Prop 1A, but it has to be matched 50:50. Matching funds will almost certainly materialize, if not from the federal government then from foreign governments anxious to pay California to buy their products (for example, Japan’s ambassador to the US offered half the money, and Japan expects China and Korea to offer funding as well). It should be enough to build an initial operable segment, though probably not to build from Los Angeles to San Francisco.

The question is then how to prioritize. The gold standard here should be building all the way from Sylmar to San Jose and electrifying the legacy lines at the two ends. At the Bay Area end, the Caltrain FRA waiver ensures this wouldn’t cause regulatory problems, and while it would limit initial capacity, it would not increase travel time by more than a few minutes. At the Los Angeles Basin end, it would require Metrolink or HSR to seek a waiver, along the lines Caltrain has already gotten; the speed reduction, while still not very large, would be larger, because the travel time simulations assume higher operating speed in the LA Basin, and there will be fewer speed limits due to curves.

Unfortunately, while cutting the initial segment to San Jose-Sylmar will save a large number of billions of dollars in urban grade separations, it may not save enough, though it’s fairly close if one believes the 2009 Business Plan numbers. If California has half the money from foreign sources, then matched with Prop 1A and existing federal money, it has a total of $24 billion, which is not enough. The question then boils down to where to go first from the Central Valley – south or north. North would involve going over Pacheco Pass to San Jose (or, better yet, over Altamont Pass to Livermore and thence Redwood City). South would involve going south to Sylmar, either through Palmdale or directly through Tejon Pass, which carries I-5; although Palmdale is the preferred alternative, the HSR Authority is looking at Tejon again. For a slide show using the existing preferred options, see here. Either alone should be doable with the money available under such a circumstance, which is about $18 billion.

I claim that the southern option is the better one – in fact, that LA-Bakersfield is more important than Bakersfield-Fresno. The reason is, first, a pure numbers game: LA is much larger than anything else in California. And second, Tejon is where the existing legacy transit options are the worst: Amtrak can’t go between Palmdale and Bakersfield at all because the Tehachapi Loop is at capacity, ensuring that a mixed legacy-high speed operation in the mold of the initial TGV runs is not possible even under reformed FRA regulations.

Northern options suffer from different problems. The Pacheco option’s problem is that it uses Pacheco, and is therefore inadequate at linking the Bay Area to Sacramento. This means nothing further can be done until enough money materializes to connect to the Los Angeles Basin. The Altamont option’s problem is that the Phase 0 option connects to Livermore and requires a transfer; connecting to Redwood City is possible, but requires all of the most expensive elements of Altamont, especially crossing the Bay in the vicinity of the Dumbarton Bridge.

Once the southern option is selected, the question is how far to go. Bakersfield-Sylmar is expensive, and although it’s easily doable given 50% foreign funding, lower levels of funding may not suffice. Bakersfield-Palmdale is much easier, and could be done on existing Prop 1A money if it were not required a 50:50 match; however, Palmdale is not in the LA Basin, and the legacy rail line to LA is curvy and steep. Express Metrolink trains do Palmdale-LA in 1:28, versus 0:27 projected for HSR. Higher cant deficiency and acceleration with electrification could cut the travel time somewhat, but not enough to make HSR competitive for travel from LA to the Central Valley. Travel from LA to the Bay Area is another issue, but a situation in which it’s possible to build all the way to San Jose is one in which there’s money to build to Sylmar.

The alternative is to use Tejon and connect to the legacy line in Santa Clarita. It’s more expensive because Tejon is one big crossing whereas the Palmdale route involves two smaller crossings, one to Bakersfield and one to the LA Basin. It should still be affordable, though I have no detailed segment-by-segment breakdown of the Tejon route’s cost. The advantage is that Santa Clarita is much closer to Los Angeles than Palmdale, and the legacy Metrolink route to Palmdale is fairly straight south of Santa Clarita; even now, express trains travel to LA in 42 minutes, half an hour slower than full HSR buildout rather than an hour as with Palmdale, and there’s more potential for an increase in speed.

That said, the debate is most likely academic – Tejon vs. Palmdale is most likely going to be decided primarily on a revisited look at the costs, with other issues (LA County power brokers prefer Palmdale, Tejon is shorter) not much more than tiebreakers. In addition, a situation in which Prop 1A money could be released for the crossing is one in which matching funds have materialized, making the full Bakersfield-LA route realistic with the available money. The primary lesson is that there should be enough money to build a realistic initial operable segment, not going all the way from LA to San Francisco but still serving a fair number of intercity travelers.