zlacker

>>CGMthr+(OP)
I cannot stop thinking about the fact that air travel wastes so much energy, just to float. Buoyancy is free.

It is insane that we are not doing materials research on how to capture vacuum in thin cavities.

>>whatev+QK2
Modern jetliners get a higher miles per gallon per seat than most US (ICE) cars. They easily beat any ICE car with a single occupant in miles per gallon equivalent. If you want to minimise fuel usage and can't find someone to share with, it's better to fly! The issue is almost entirely the distance travelled.

>>SPICLK+jP2
now do high speed rail..

>>riirif+D93
It varies so much depending on passenger occupancy rates. Planes tend to run near 100%, and cars (at least in the US, although I'm sure other countries aren't much better) at near 20%.

Assuming 1mpg for the entire train, it needs at least 100 passengers to compare to a fully-occupied passenger plane.

>>SPICLK+Oa3
Can you name a HSR route that exists between US cities that would challenge the near 100% occupancy rates? Seems relevant. We probably need to compare routes where there exists air travel and HSR to draw any occupancy rate choices, but this is clearly an aside.

The point is that it makes air travel ludicrous from an energy perspective where rail at high speeds (200mph) is possible

>>ririfd+rc3
Edit: Now you've clarified your question.

There's nothing special about HSR when considering fuel (or energy) efficiency, except that it's probably less efficient over all due to increased air drag, and that it needs very particular infrastructure and passenger demand to make it work.

I'd hazard a guess that many (most?) flight routes are nowhere near popular enough to make them viable for train replacement.

Eg. The bullet train in Japan has a peak capacity of over 20,000 passengers per hour.

The most popular flight route in the US has around 3 million passengers per year, or ~340 an hour.