If we had a rail system instead of an interstate road system, the same thing would be said about highways.

In fact, the cost of building & maintaining the highway system is quite astronomic.

Highways are far more useful than HSR. They can connect much more than hub-to-hub, they can be used 24/7, they can be used by a wide variety of vehicles supporting a wide variety of industries. HSR is just for passengers.

If we were designing the interstate system today, that's actually a fun thought experiment. What would we change? I would probably focus more on throughput -- cars can be half as wide and still seat tons of people, 5 lane highways today could easy be 8 lanes of narrower cars.

Narrow vehicles are unstablea. A narrow vehicle capable of carrying 7 people would be ridiculously long, and impossible to park.

There have been several studies that more lanes tend to lead to more traffic, not less. Here's a wiki article about the phenomenon: https://en.wikipedia.org/wiki/Induced_demand

That really depends on what you mean by more traffic. I think there are very few examples of extra capacity increasing travel time.

As you point out, several studies have shown that over time, travel time converges to the same value, despite additional capacity.

However, I think it is important to note that more lanes means more people are still getting from point A to B.

That's the point. More traffic more throughput. Nobody's saying the user experience is going to improve.

Peak hours are always going to cause congestion.

Wrong. More lanes doesn't lead to more traffic unless there are way too few lanes in the first place. I know of plenty of places where adding more lanes would not add more demand - North Dakota is full of them for example.

The only problem is we can't afford to build enough lanes. There is a limit to how wide you can go, and up or down is vastly more expensive than at grade. We could do it if we wanted to spend the money - but most such places find that a better bus and (not or!) train network is a better investment.

That's not necessarily a bad thing by itself. It means more people get to go where they want to go. But of course that can cause some negative externalities.

Creating more throughput instead of a quicker route isn't the same as saying "more lanes do nothing." So maybe your new highway lanes didn't cure congestion, but they did help alleviate housing demand some by letting more people commute with the same (albeit bad) commute time.

Yes, exactly. They said they're focusing on more throughput.

> If we were designing the interstate system today, that's actually a fun thought experiment. What would we change? I would probably focus more on throughput -- cars can be half as wide and still seat tons of people, 5 lane highways today could easy be 8 lanes of narrower cars.

Why would you go narrower? That makes problems worse for trucks and other cargo conveyance; note that in general, newer highway standards tends to increase lane width, not decrease them compared to older standards.

(I guess you can see the same effect with railroads--the UK railroads have smaller loading gauges than newer networks like the US, Germany, or Sweden).

In this thought experiment, we'd be able to redesign the whole road infrastructure. I'd say mandating smaller cars would be a huge savings in general.

I'm now imagining higher power Renault Twizys everywhere

Which is why these developments (faster rail and maglev) are so exciting. They change the economics of the travel decisions, potentially putting more connections into the "economically feasible" category. Of course, that's also dependent on construction & maintenance costs. I'd be interested to see where / if there are chances for economies of scale for maglev that are simply not there yet due to the tech's non-prevalence.

If it takes only marginally more, or even less time to travel by train than by plane, I'm taking the train any day.

A Shinkansen going from Boston to DC would be massively profitable.

And I'm talking above 120mph. None of this 70mph "high speed" slow stuff.

High speed railways are not that expensive. I'm not talking about 700km/h but around 300km/h.

Spain has plenty of them, according to Wikipedia only China has more. And if I'm not wrong, Spain is building them in other countries too.

https://en.wikipedia.org/wiki/AVE

https://www.pbs.org/wnet/blueprintamerica/video/web-exclusiv...

I seriously question "massively profitable", especially if you do it as a private company. You'd have to buy the right-of-way, and then pay taxes on it every year. That's some pretty expensive real estate. Then, the maintenance requirements on high-speed rail are pretty stringent. That costs, too. It's not just the cost of the train crews and the electricity (or fuel) that you have to think about.

If you've got real numbers, I'd like to see them.

I was thinking a retrofit of existing rails as well as an eminent-domain type acquisition of the land.

Eminent-domain doesn't solve the cost problem. You still have to pay for extremely valuable land.

Most of the existing tracks aren't straight enough for high speed rail.

The Acela is already above 120mph where it can. The biggest problem area is actually in Connecticut, and half of that issue is Metro North's fault, not Amtrak. (The other half is that the line is legitimately too curvy to support 120mph speed in large places, but Metro North is why it struggles to hit 70mph at times).

Which makes me wonder ...

How do you secure a railway?

If trains go 600 kph, do we get a TSA circus along the length of all railtracks? Is this even feasible?

You just don't, it's not really needed.

Never underestimate the poder of idiots in large amounts.

"hundreds occupied high-speed railway tracks for around 3 hours, blocking services linking Figueres, Girona and Barcelona,"

https://www.thelocal.es/20181001/pro-independence-protesters...

A thick log or dead deer across the tracks of a high speed train could lead to catastrophe.

I once rode the Eurostar from London to Paris and as I recall all the high speed sections were enclosed in very high, barbed wire fence. So some security is definitely needed. Collision energy goes up with the square of velocity.

The US doesn't build high speed rail between large cities that are a medium distance apart either.

True.

I see that mostly as part of the larger problem that the US doesn't build much of anything these days.

The US might have a low population density if you just take the population divided by the territory but it's obviously all in the geography and clusters and averaging is not helpful.

The US has several population clusters[1] and for example the Northeast corridor in particular with 50 million inhabitants is a reasonably good target for a high speed rail network.

[1]https://en.wikipedia.org/wiki/Northeast_megalopolis#/media/F...

How about: Boston - New York - Philadelphia - Washington - Chicago?

Only Disney can do this, it seems, and the mexicans will pay for riding it