Comment by selectodude
9 years ago
If subways are already as tight as sardine cans, how would giving everybody in that train a full car full of room even be the slightest bit possible? There just isn't enough physical room in the tunnels for that.
9 years ago
If subways are already as tight as sardine cans, how would giving everybody in that train a full car full of room even be the slightest bit possible? There just isn't enough physical room in the tunnels for that.
Running at the proposed 100+ mph should provide the necessary throughput (and actually require seating - have fun with those gs while standing).
The problem is that there are diminishing throughput returns to velocity. You need massive amounts of duplicated track for that to be feasible...on and off ramps for every entrance and exit. On and off ramp lengths grow exponentially relative to target velocity. That might be fine for long distance travel, where on and off ramps can be concentrated in few locations...urban travel not so much.
> On and off ramp lengths grow exponentially relative to target velocity
Centripetal acceleration on a curve with radius r is (v^2/r) so it seems that it grows quadratically, not exponentially.
Exponential growth would mean that the v appears in an exponent in the formula.