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Comment by thatoneguy | Hacker News Reader

From my skimming of the PDF, it sounds like a pneumatic tube transportation system with a compressor fan on the front of the vehicle that moves high-pressure air from the front to the back maintaining a low-pressure state around the vehicle. Kind of like an Earth-bound Alcubierre drive.

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The pumped air is also used to create an air cushion around the pod to keep it suspended at high speeds. Also, solar panels line the top of the tube so that it is self powering.

If this is going to be running above ground, how do they purpose to find space to even build this?

http://mappery.com/maps/Los-Angeles-California-Transportatio...

My only guess would be to build it vertically. . which is were everything is going anyways, right?

Pylons above the existing I-5 freeway.

It would not be built anywhere on the map in your link. The LA station is in Santa Clarita which is further north and west. It seems to me that he has laid out a route that avoids as much as possible dense urban areas. Even his extensions out to Vegas and San Diego by pass most of the urban development in the LA basin.

Does it support multiple pods in the tube at once?

Yes but they need to be 5 miles apart so they would board approximately every 30 seconds and carry 28 people each.

Yes, a pod would depart every 2 minutes or less, which puts about 23 miles between them.

I think it's actually more useful to think in terms of "2 minutes between them", as opposed to "23 miles".

2 minutes is all you have - to detect the situation, make a decision, then stop.

How much time do you have in heavy freeway traffic?

Four seconds, if you're driving the way you were instructed. But you've got multiple options: go left or right, and if you slam the brakes they'll stop you in time. If something broke the tube, are we looking at several pods slamming into the obstruction one after the other?

The two situations you're comparing are vastly dissimilar.

Yes, but no discussion of how you'd bring the system down if one broke down mid-trip or how you'd bring it back up. The individual cars only carry power to maintain speed, no to accelerate, so if they have to stop because something goes wrong, a whole bunch of people are stuck in the middle of nowhere without a toilet (or air?)

There's some discussion on pages 52-54 of the PDF.

I stand corrected. In fact it comes down to two paragraphs and doesn't really cover much including, for example, just how long this would take (the cars behind the stalled vehicle would use emergency brakes then proceed at low speed on wheels to the nearest station -- sounds like at least half a day of down time).

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