I know Hyperloop has a ton of naysayers -- partly because the initial price tag of $6 billion is most likely a severe underestimation -- but...
It has the potential to make a tremendous impact on society, much more so than self-driving cars in my opinion. Just as a simple example, imagine what would happen to the Bay Area housing market if people could live in a ~300 mile radius and still get to work in downtown SF in less than 30 minutes.
I think the only game changing thing about the hyperloop is that it is getting rich people excited about public transit. I mean, my guess is that we're never going to get a SF <-> LA transit path that is faster than a airline with a "skip the security" pass; I don't believe that the hyperloop as envisioned will never be built.
I know that sounds trivial... but it's not. Public transit is a failure in America in large part because wealthy people, even wealthy people who support public transit in general, don't want public transit near them.
> even wealthy people who support public transit in general, don't want public transit near them.
This seems very odd to me. Here in the Netherlands, housing prices actually increase when there's good public transport. In the north of Amsterdam a new metro line is being built, which is already causing an increase in housing prices there.
For instance, biking to school or work in the US means you are kinda poor or a cheapskate (not for everyone, and not in densely populated cities such as DC/Arlington, SF, NYC and Perhaps Boston)
On the other hand, in Europe I've seen deans biking to school and the feeling is exactly the opposite ("wow that's so cool!")
Sorry for generalizing, but that was what I saw, having lived on both sides
Really? Have you ever tried to get from the train station of, say, Blaricum or Bloemendaal to anywhere else there? 'Wealthy' people don't live in houses whose prices are affected by availability of public transport, in the Netherlands. (OTOH I wouldn't say that they 'don't want PT near them', but then again that's not really true for other places either).
This is true, but we're talking SF & LA here, metropolitan areas. Blaricum is better compared to something like the Hamptons. There is no public transport because there's space to park cars, so public transportation is not necessary and it's impractical since the population is spread out.
The Apollobuurt in Amsterdam is also full of rich people and yet there's a lot of public transportation. The people living there are not against public transportation though.
Public transit is not a failure in the US, it's just very uneven and it's a big country. Moreover, the US especially suffers from the "lost decades" of urban decay through the mid 20th century. There was a sweet spot for initial public transit infrastructure investment around the turn of the 20th century and a lot of cities in the US missed it, with a much bigger hill to climb today.
Public transport in the US is generally a failure because we try to build static systems in low-to-moderate density areas with dynamic population change.
I.e. putting a $30 million light rail system in a "business corridor", then watching market forces move businesses away from it 5 years later and wondering why no one rides the trams.
I should say hundreds of millions. This[1], for example.
Munis sell these projects on the "expectations that the corridors will attract much economic growth," but the finished product has shown not to be a reliable multiplier of community investment and development.
5 years ago you probably would have said "we can't have a self driving car... there is <problem1> that we can't surmount." Yet, now we are on the brink of it. Hell, even at the start of this year I would have laughed if you said we will have aerial drones delivering amazon goods. Yet, here we are with a pretty impressive POC from amazon. we can merge onto a freeway why can't we merge these hyperloop pods so we can have many stops?
Because deceleration takes time, unless you want to be flattened to the front of the vehicle. The more stops you have, the lower the overall speed will be at which this thing operates. High-speed trains in Germany that can drive up to 350 km/h often only average around 120 km/h over their total distance because with stops in between you spend a lot of time accelerating and decelerating. And where stops are more frequent you can't even reach the full speed since you have to start breaking already before you're done accelerating.
There's nothing inherent in physics that prevents self-driving cars, but unless you want to jump out of a moving hyperloop pod, it has to come to a stop and accelerate again; and it does so slowly enough not to kill its passengers.
I think we can tolerate about 0.5g of deceleration, which shifts the direction of gravity by 30 degrees. So, about 5ms⁻². To get to interesting speeds such as 500ms⁻¹ (about mach 1.5), it would take 100 seconds, and 25,000m (25km, or about 15 miles). Assuming maximum acceleration and deceleration, it would take 3 minutes and 20 seconds to travel over 50km. At first approximation, separating stations by 50km looks doable.
But that's not the whole story. If we have intermediate stations at all, we need to ensure all cars have the same speed when they get to share the same main tube. We need acceleration tubes the same way we need acceleration lanes in regular roads. (How to plug those tubes to the main one is left as an exercise to whoever builds this.) Anyway, those tubes need to be 25km long.
But that doesn't mean they have to be separated by that much. You could have a station every 5km if you're willing to run 5 acceleration lanes in parallel (and pay for them).
This gets even easier once you get close to the destination: even in the main tube, cars need to decelerate, starting at 25km from their destination. 10km away for instance, the speed is already down to a little over 300ms⁻¹. To join the lane at that point, you need only 10km to accelerate. Likewise, if you need to join 5km before the destination, you need to accelerate for 5km as well.
In other words, you could very well have stations as close as 5, 10, or 20km from the urban centre. You won't go very fast, but remember that at those speeds and accelerations, it's going to take less than 5 minutes anyway.
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If trains didn't have to stop at every station, and used acceleration and deceleration rail-roads where appropriate, their average speed would be much higher. First, they can't for 2 reasons: rail-roads are expensive and take land (so does an Hyperloop tube). Second, passengers need to go in and out. This means many stops for the same train. Hyperloop's uses individual, so it doesn't have that problem.
> I think we can tolerate about 0.5g of deceleration
Untrained human beings can handle minutes of linear deceleration (perpendicular to the spine) at 12 g, and at least a second at 25 g. Strapped, mind you. And the limits are higher in backwards-facing seats (eyeballs-in is ~17 g untrained) with the additional advantage that very little strapping is needed.
to be fair the test that showed a lower bound on survive-ability caused the fellow eye damage. (wikipedia says it was measured at a peak "eyeball out" g-force of 46.2g and 25g for 1.1 seconds.)
I'd say 1-2g over a span of a few min might be tolerable by the general population but might not be need to be researched for suitability for children, the elderly, and the disabled.
There are a lot of strategies for handling this. One of which is, accelerate the pods on a separate, shorter (semi-circular?) track before merging into the main "pod stream". Similarly, decelerate on a separate, shorter (semi-circular?) track. There was some prototype (or theory) of this discussed in a link on HN several months ago in which a Chinese train station accelerated (or decelerated, I forget) a car to match the speed of a passing train to append that car to the train as it went by.
Just because you need to accelerate and decelerate doesn't mean you need to do it on the same shared track as the main line.
In the same spirit, small pods allow far more flexibility than a bus. With small enough pods, i stop at my destination only, rather than every destination that anyone needs. I'd guess 4 or 6 is a useful size, about the same as cars.
4 years ago I was telling people we would have self driving cars in 5 years. So I'm very pleased with the progress.
It remains to be seen how effective pumping can be, but as envisioned hyperloop is a point to point system. Switches are very difficult and must be done at low speed a) because of the slipstream disruption and b) because branching greatly increases the interior volume of an enclosed tubeset. It can be done.. but it's a level above the basic infrastructure.
You can't have it in every town, but you could hit a bunch. And probably not 30 minutes, but maybe 1.5 hours.
Chicago's train system has 241 stations and carries 300k people a day. The furthest station is 62 miles from Chicago.[1] Takes more like 1hr 40 min. New York's train system has to be more more active.
1-Motorola was dumb enough to build a campus out there and then never used it.
300 miles in 30 minutes is extremely challenging to do with a spoke-and-hub model. Anyone who rides transit regularly will tell you that waiting at transfer stations can easily overwhelm actual in transit time.
So, changing the Bay area housing market is a "much more tremendous impact" than self driving cars?
Maybe you haven't thought this through. Self driving cars are likely to create world wide significant changes to mass mobility. The bay area is a drop in the bucket in comparison.
I doubt it will be like current rail systems with multiple stops. There will probably be a very few stops, likely once every hundred miles or so. Getting to downtown SF within 30 minutes is unlikely for the vast majority of people within that 300 mile radius, Hyperloop or not.
Too bad I can't think of anywhere within 300mi that is both (a) large enough to justify a hyperloop stop and (b) isn't an awful hellhole (Fresno). Maybe east of Sacramento?
hyperloop will not solve this problem just as any FIXED point transportation system cannot. Autonomous driving will serve far more people where they want and when they want than any fixed point system. Autonomous buses can move people in large numbers and is infinitely adjustable to changes in usage patterns
Now it might be possible that something like this could reduce the need for short hop flights. Even if it did not I would put both end points onto existing airports to take advantage of the existing infrastructure that already serves them.
I don't think it matters which one is better - each has a niche to fill. I would much rather hop on a train and be in LA or Seattle in an hour, than get a self-driving car and be there in 6+. But for short distance, cars or a slower, more traditional public are the better option (mainly because you can't have high-speed lines to carry people a few blocks at a time)
It has the potential to make a tremendous impact on society, much more so than self-driving cars in my opinion. Just as a simple example, imagine what would happen to the Bay Area housing market if people could live in a ~300 mile radius and still get to work in downtown SF in less than 30 minutes.