[tptacek]

The top operating speed of the TGV is in the neighborhood of 230MPH, isn't it?

If you can cost-effectively deploy rail that averages 300MPH, rail becomes more attractive. But the average speed of the Shanghai Maglev is 155MPH. It's nothing close to 300MPH.

It is extraordinarily unlikely that any train using current technology is going to average 200MPH between Chicago and Houston. Even with TGV-comparable trains, the trip from Chicago to Houston will take 8+ (heh) hours --- and that presumes an expenditure of public resources unparalleled in the last 50 years... all to get to a place where it would still be still be irrational not to take one of the many tens of airliner trips between those two cities every day.

[jdlegg]

Unattributed, but per Wikipedia: "In mid-2011, scheduled TGV trains operated at the highest speeds in conventional train service in the world,[citation needed] regularly reaching 320 km/h (200 mph) on the LGV Est, LGV Rhin-Rhône and the LGV Méditerranée." [0] You're right, though, that this is different than average speed.

Still, 300 mph would be a stretch goal for sure, but it doesn't seem ridiculous if you're starting from scratch today. The Shanghai system was built over a decade ago. At minimum, automated computer controls should be significantly improved.

I'm also operating with the assumption that the budget for such a project would be unlimited, since it's just a thought exercise.

[0] http://en.wikipedia.org/wiki/TGV

[tptacek]

Again: average speed. Peak doesn't matter. Your stretch goal doubles the average speed of one of the fastest trains in the world, running on a route built from scratch to accommodate it.

[jdlegg]

I'm thinking boldly here. The French are able to peak at 200-230mph on operating trains running on conventional track. The Japanese and Chinese can push Maglevs up to 360+ mph. As a "disruptive" technology, 300 mph seems like it's attainable or at least worth considering.

It may require new approaches. It would be a monumental engineering effort. It would probably ensure full employment for a decade or more. But I don't think it's any more ridiculous than, say, sending a manned mission to Mars.

[bhousel]

What you're describing is a Hyperloop, not a high speed rail.

[jdlegg]

Fair enough.

[boracay]

It's pretty silly to compare the average speed of the Shanghai Maglev. It's like a 7 minute trip with 1 minute at top speed. There's several, traditional HSR, routes in china with faster average speeds.

[tptacek]

The Paris-Lyon TGV averages 140MPH. Wuhan-Guangzhou managed to average 195, but was reduced to 186. Beijing-Tianjin 146. Japan has 130-145MPH. So:

* None of these average speeds would make Chicago-Houston competitive with air. Even if you add the hour on both ends for the air trip, the fastest train in China operating above the Chinese speed limit still loses to Southwest Airlines.

* None of these average speeds make a 300MPH average speed train any more realistic.

[melling]

You're a funny guy. An hour ago you were quoting peak speeds.

https://news.ycombinator.com/item?id=8712943

[tptacek]

Once again: I was comparing the peak speed of one rail line to that of another. Read in context. This snark doesn't even make sense on this part of the thread.