Comment by xt00 | Hacker News Reader

Comment by xt00 | Hacker News Reader

I have observed high speed rail lines in Asia and Europe and there is one commonality — a very large percentage of the rail lines are built either on elevated tracks near populated areas, or underground for sections. While this certainly adds cost, it seems to me (would love this to be confirmed by somebody who knows) that the costs are more likely to be closer to the projection. It appears in the US many of these plans rely upon lower costs where the train is built on the ground. So they end up building tons of small bridges, regrading roads, moving wires, moving drainage, communication equipment etc as the train interacts with existing infrastructure. All of the unknowns of hundreds of miles of that ends up costing tons of money and risk. So you have some consultant saying “well elevated costs 2x what doing it on the ground does” or something and in the end they build it on the ground for 4x the original cost due to having to handle zillions of little motivations all over the place. My take — just elevate it and simplify the situation. It ends up being basically the best of all worlds in the end.

Yeah, that was the original sin of the CAHSR project. They drew some lines on surface freight rail lines and said "we'll build it here". But they actually cannot build it "there", they have to build it over or under "there", which gets extremely expensive. Foamers never got this, HSR is more like a new freeway than the Southern Pacific.

In Europe, it seems like HSR stations are often in greenfield locations outside of town. In California it became some hypothetical "downtown revitalization" scheme. But Bakersfield etc really should want better local public transit.

> In Europe, it seems like HSR stations are often in greenfield locations outside of town.

This is not true at all. If this were the case, it would thoroughly defeat the core advantage of HSR over air travel: fast connections between city centres without requiring passengers to travel to some far-flung port of call, adding an additional two hours at least.

All the Gares, Hauptbahnhofs, Staziones, Estacións, and St Pancrases of Europe are bang smack in the middle of their respective cities, and almost all predate the introduction of HSR by around a century or so, barring renovations here and there. The only truly brand-new HSR stations are in Japan and China.

Plenty of HSR within European cities use existing infrastructure and 1435 mm standard gauge, and travel at lower speeds to account for this. The trains usually only get up to speed as they leave the city and enter dedicated high-speed railways with grade separation, concrete sleepers, reduced turning radii, etc.

That's what I mean by foamer logic, most of that American passenger rail stuff went defunct a hundred years ago. Fresno has 20mph vegetable trains and now a 20 mile long HSR viaduct to "revitalize" (blight) their pathetic downtown. There's no money for all the tunneling they want to do. (Take a look at the EIRs.)

The French came here and recommended a greenfield route, which is what they built in France, you can see the bypasses on google maps. They concluded that California is full of shit, and built HSR in Morocco instead.

You can easily look and confirm this. The current central valley part of the project is mostly grade separation projects. There is something like 30 of them. Not including a half dozen really major projects. Either where the line goes through a city, crosses a river, or over an existing rail line.

My take is there are a bunch of reasons to build the thing. None of them on their own is convincing but taken together it's reasonable.

Things like.

All the major airports in California are maxed out and expanding them would be near impossible or very expensive. You can look at costs to do that in non US countries. I think $15 billion for two runways at Heathrow. Imagine doing that times six.

Growing population in the central valley makes the current at grade rail crossings untenable.

Distinct lack of high speed commuter rail in the major metro's.

> a very large percentage of the rail lines are built either on elevated tracks near populated areas, or underground for sections

This is absolutely not true in France, where the TGV mostly takes regular lines to exit the suburbs of every city it goes through.

> It appears in the US many of these plans rely upon lower costs where the train is built on the ground. So they end up building tons of small bridges, regrading roads, moving wires, moving drainage, communication equipment etc as the train interacts with existing infrastructure

Building elevated is a shit-ton more expensive

Yea the costs for sure will vary a bunch -- but just searching around a bit I found this: https://pedestrianobservations.com/2012/09/25/relative-costs... That cites some Danish study about elevated vs. non-elevated costing roughly 2-2.5X. Really my point to highlight is that building on the ground ends up in reality being far more complicated than piling up ballast and sleepers on the ground and mounting tracks to that and assuming you don't have many roads. Of course if you are crossing vast areas with virtually no roads or infrastructure, yes use the cheapest option, but in the areas where its just one complicated crossing after another, then you end up with tons of "mitigations" as they call it costing tons of money -- and when that is properly factored in, the cost difference is far less than expected.

That's great that France has the TGV mostly on the ground as they exit the suburbs of every city -- whats the typical configuration of the crossings for roads? Does the road basically go in a small tunnel under the crossing or does the track become elevated temporarily? Or do they actually allow cars crossing the tracks at grade?

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