4 ms·

There are plenty that average 200mph and the Chinese seem to be getting a bit higher, with one operating at 286mph. They are working on considerably faster ones

There are plenty that average 200mph and the Chinese seem to be getting a bit higher, with one operating at 286mph. They are working on considerably faster ones. Surely a US train could aim to be up there with the fastest? Even with that boost though, your point remains. https://amp.cnn.com/cnn/travel/article/worlds-fastest-trains-cmd/index.html https://amp.cnn.com/cnn/travel/article/worlds-fastest-trains...

nradov 4y ago
There's no way any future US bullet train could hit 200 mph through the Sierra Nevada and Rocky mountain ranges unless we bore tunnels straight through. Transcontinental bullet trains across North America are a total pipe dream just based on simple geography. But bullet trains should play a role in our regional transportation infrastructure.
qbasic_forever 4y ago
Our rail system is built for slow speed freight hauling and passenger trains have to share the same rails (and give priority to freight, which is why we have enormous unexpected delays on our passenger trains). It's simply not feasible to run bullet trains in the country without building entirely new tracks. It is an enormous and expensive undertaking to build new rails across 2600 miles, through a couple enormous mountain ranges and more.
godelski 4y ago
Note that I calculated with 200mph and did not consider stops or a train's need to travel not in straight lines. Kube made a comment comparing with Japan's system that may extrapolate better as it considers stops[0], but may bound from the other direction as there are likely higher demand for stops along that route than SF to NY, which is mostly traveling through low population dense areas. Consider that my napkin calculation was intended to give many advantages to the train for a naive best case scenario. Also note that while the Shanghai Maglev does have a maximum speed of 268mph it has an average speed of 139/155mph (different schedules = different speeds). We need to consider average when calculating travel times. You'll also note that on that CNN page that several of those trains have test runs that reach near 400mph! This is good for considering where we might be able to get with high levels of optimization but they do not reflect the reality of speeds that a passenger will actually experience. Considering the extrapolations we'd realistically need trains that could have max speeds above 600mph and sustained speeds (through quite windy areas and mountains mind you) of 400+mph. I do think cross continental passenger trains can still have a market but I think more coastal focused lines will have substantially better markets and we shouldn't expect trans-continental train alternatives to planes being popular for quite some time. The coastal lines mostly make sense because the total times are still relatively short and we consider the convenience tradeoff more influential. I'm pretty sure that this trade-off is highly non-linear with respect to travel time (convenience weakly dominates in short transit but time strongly dominates on long hauls). [0] https://news.ycombinator.com/item?id=34549637 https://news.ycombinator.com/item?id=34549637
- qbasic_forever 4y ago
  Getting trains up past 600mph is going to be right at breaking the sound barrier. There's no way communities and people living near tracks would put up with constant sonic booms all day. It's just not feasible.

nradov 4y ago

There's no way any future US bullet train could hit 200 mph through the Sierra Nevada and Rocky mountain ranges unless we bore tunnels straight through. Transcontinental bullet trains across North America are a total pipe dream just based on simple geography. But bullet trains should play a role in our regional transportation infrastructure.

qbasic_forever 4y ago

Our rail system is built for slow speed freight hauling and passenger trains have to share the same rails (and give priority to freight, which is why we have enormous unexpected delays on our passenger trains). It's simply not feasible to run bullet trains in the country without building entirely new tracks. It is an enormous and expensive undertaking to build new rails across 2600 miles, through a couple enormous mountain ranges and more.

godelski 4y ago

Note that I calculated with 200mph and did not consider stops or a train's need to travel not in straight lines. Kube made a comment comparing with Japan's system that may extrapolate better as it considers stops[0], but may bound from the other direction as there are likely higher demand for stops along that route than SF to NY, which is mostly traveling through low population dense areas. Consider that my napkin calculation was intended to give many advantages to the train for a naive best case scenario. Also note that while the Shanghai Maglev does have a maximum speed of 268mph it has an average speed of 139/155mph (different schedules = different speeds). We need to consider average when calculating travel times. You'll also note that on that CNN page that several of those trains have test runs that reach near 400mph! This is good for considering where we might be able to get with high levels of optimization but they do not reflect the reality of speeds that a passenger will actually experience. Considering the extrapolations we'd realistically need trains that could have max speeds above 600mph and sustained speeds (through quite windy areas and mountains mind you) of 400+mph. I do think cross continental passenger trains can still have a market but I think more coastal focused lines will have substantially better markets and we shouldn't expect trans-continental train alternatives to planes being popular for quite some time. The coastal lines mostly make sense because the total times are still relatively short and we consider the convenience tradeoff more influential. I'm pretty sure that this trade-off is highly non-linear with respect to travel time (convenience weakly dominates in short transit but time strongly dominates on long hauls). [0] https://news.ycombinator.com/item?id=34549637 https://news.ycombinator.com/item?id=34549637

qbasic_forever 4y ago
Getting trains up past 600mph is going to be right at breaking the sound barrier. There's no way communities and people living near tracks would put up with constant sonic booms all day. It's just not feasible.