
Why Nonstop Travel in Personal Pods Has yet to Take Off - larubbio
http://www.npr.org/2015/09/24/440859459/why-nonstop-travel-in-personal-pods-has-yet-to-take-off
======
1024core
Having taken MUNI (SF's light rail) underground in SF, I have some doubt about
the efficiency of such a system. In my station (Church), in the morning, I can
see trains coming in every 3-4 minutes or so; and about 40 people get on at
once. With a PRT system, you'd have to first line up at the turnstile to punch
in your destination. Assume 15 seconds each. Then, when a car comes in, you'd
have line up to get in. A person gets in, swipes her card, punches in the
destination, etc. Minimum time: 1 minute, _if_ you're being fast. Suddenly,
the bandwidth is just not there; the platform becomes the bottleneck. Same
would happen at an elevated pathway too, I imagine.

So, a system like this would be infeasible in a dense city like SF. Above
ground is another story altogether: the NIMBYs would block all construction.

What _could_ work is a system of autonomous vehicles (taxis) the size of a
Google self-driving car, running above ground, summoned via a smartphone app
or a kiosk at every corner. So, instead of dedicated pathways and elevated
tracks, use autonomous cars.

Also: very importantly, each car _must_ have odor detectors / biohazard
detectors in case someone has an 'accident' in the car.

~~~
ChrisLTD
All excellent points. This is why we should invest more heavily in proven mass
transit systems rather than divert limited public funds into these inefficient
pods or hyperloop systems.

Corollary: Is it really that bad to have to ride a bus or train with other
people on-board?

~~~
rm_-rf_slash
Busses are the least-worst alternative to walking. People are noisy, they
smell, they crowd you when you're holding groceries, they make a trip with
friends or God forbid a date unpleasant, they're late when you're early and
early when you're late, and chances are you'll still have to walk a few blocks
to get where you want to go.

Obviously not every case, but I've taken a fair amount of Bay Area busses in
my time and there was always at least one of the above complaints.

~~~
ChrisLTD
Agreed that it's not as pleasant as having a car to yourself (I ride the NYC
buses and subways everyday), but I think we could solve a lot of the people
issues with proper policing rather than outright isolation.

~~~
rm_-rf_slash
Chances are if you make more "quality of life" laws you'll either have some
schmuck causing trouble when enforcement is nowhere to be found, or they'll be
used as excuses for cops to pad their stats by arresting first and asking
questions later, with most of the punishment hitting minorities, as tends to
happen in the U.S.

The problem is cultural. Another poster here mentioned Japan, where busses are
pleasant. After all, that is a place where "the nail that sticks up gets
hammered down." If we really want public life on par with Japan or Europe,
change has to start with each and every one of us. No government program or
well-funded startup could ever do it alone.

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rm_-rf_slash
Here in Ithaca, NY, we have three major communities that are relatively close,
but _just_ too far away from a combination of distance, elevation from hills,
and miserably cold temperatures: downtown, Ithaca College, and (Cornell's)
collegetown. A simple pod connection between collegetown and downtown, and
then another route to IC, would do wonders for our transit system.

See, the nice and terrible thing about Ithaca is that it's a small valley
hemmed in by hills on three sites and a lake to the north, so most things tend
to be bunched together, which can be almost walkable, depending on distance,
temperature, and whether you're carrying groceries. The downside is that there
are like 5 arterial roads to get anywhere meaningful in the area, and if just
one of them is closed for construction, traffic slows to a halt.

We don't need long or complex routes. I've been on the WVU pods, and while
they're nice, they go FAR. I'm talking about a quarter or less of the distance
they cover, and only in two directions (and maybe a third because you have a
better chance of getting into Willy Wonka's chocolate factory than finding
parking at the farmers market). So please, by all means, if you're looking to
trial travel pods somewhere, start here.

~~~
Animats
That's a good application for Intamin's Mountain People Mover.[1] Intamin
builds both roller coasters and monorails, and for a ski resort, they combined
the technologies. It's a personal rapid transit system which runs on roller
coaster track. Steep hills are not a problem. Nor is snow.

[1]
[http://www.intaminworldwide.com/transportation/MountainPeopl...](http://www.intaminworldwide.com/transportation/MountainPeopleMover/tabid/119/language/de-
DE/Default.aspx)

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tkinom
They might want to try these approach:

1\. They should convince company with $$$ such as Google, FB, Apple to build
this for building between their campus buildings.

    
    
       Those company has $ and regulation issues might be might a lot smaller compare to convincing a city like SF to do it.
    
       Might be easier to sell because of the "cool factor". 
    
       Those companies can easily convince City of Mountain View, Sunnyvale, Cupertino to let them do it.
    
    

2\. If #1 works, those companies can build routes between the public transit
hub, large shopping malls to company. Help ease the parking/commute issues.

3\. Convince Disney Land, World to do this for the "cool factor".

4\. All Major convention centers, sport stadium to build routes to major
shopping mall/large parking structures nearby.

~~~
ericras
Disneyland had one and they ripped it out 20 years ago:
[https://en.wikipedia.org/wiki/PeopleMover](https://en.wikipedia.org/wiki/PeopleMover)

Of course, it was just a "ride" and only covered Tomorrowland. I've always
thought they made a mistake not covering the whole park with one of these.

~~~
zyxley
> I've always thought they made a mistake not covering the whole park with one
> of these.

Appropriately enough given the topic at hand, they have a train for that.
[https://en.wikipedia.org/wiki/Disneyland_Railroad](https://en.wikipedia.org/wiki/Disneyland_Railroad)

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martythemaniak
I've been thinking about this a lot and think there's a few things to think
about.

First, the reason we haven't seen these is because until very recently the
tech needed to make them cheap wasn't there.

Second, the technology seems to be caught a classic "worse is better"
situation. The actual PRT tech is clearly superior to buses and LRTs, but
those are well understood and there's a simple evolutionary path (car, bus,
bus lane, lrt, lrt lane, subway). PRTs require a leap of thinking from people
and governments don't have any incentives or mandate to take such risks.

Third, PRTs tracks may be hard to connect to a true network where pods
seamlessly switch between tracks.

Finally, the self driving car could very well kill this in its tracks, but no
form of transport can deliver speed or consistency without a dedicated right
of way, be that suspended track, tunnel, marked lane etc.

~~~
rm_-rf_slash
Self-driving cars will likely kill PRT ambitions by being a better band-aid
for long enough to not have to think about the problem for a while, like how
successive attempts at solar power were buried for more than 100 years by more
efficient coal extraction, then oil, then nuclear, then oil, again.

~~~
eridius
Self-driving cars aren't a band-aid. In the long term, where every vehicle on
the road is self-driving, then they're the best solution possible (for any
travel distance that doesn't warrant something like Hyperloop / planes /
trains). I say this because self-driving cars can go everywhere (that cars can
go). Pods have a fixed track, they can only go where there's track to go. The
only way for Pods to be better than self-driving cars is if we rip up all the
roads and replace the entire road network with a pod track network, but that
obviously will never happen (and even then it's not necessarily better,
because a pod track network could only be used for pods, but roads can be used
by a lot more than just cars).

~~~
Zach_the_Lizard
Self-driving cars would still be less workable than rail when there's a
certain level of density. I can't see New Yorkers all loading up in self
driving cars; they just don't scale as well as trains do. Even assuming
quadruple capacity from the roads, you would still need a large number of
fairly beefy bridges and tunnels to get everyone coming from outside of
Manhattan into Manhattan.

~~~
nulltype
In what way do they not scale as well as trains do? I think self driving cars
will probably introduce a huge pile of problems, but that particular claim
seems odd to me.

~~~
Zach_the_Lizard
It comes down to space. Cars occupy way more space per passenger than trains
do. A fully loaded subway train can easily carry almost thousand people. The
7000 series in the DC Metro carries ~175 people per car maximum, and the
trains are 8 cars long, for 1400 people per train. Normally, 26 trains per
hour are scheduled during rush hour, allowing up to 36,000 people per hour if
all trains were 8 cars long (they currently aren't due to power constraints).
Other systems that have longer trains, better headways, and better seat
configurations have way higher capacities. New York for instance could achieve
much greater capacity given its longer trains and a modern signalling system.

By contrast, a road lane (which uses the same space) currently typically
carries around 1000-2000 cars per hour. In ideal circumstances it can be
almost 5000 cars per hour. Even assuming quadruple capacity from self driving
cars (not realistic), 20,000 cars per hour in ideal circumstances would
compete with trains at a far higher environmental cost.

But in more realistic scenarios with quadruple capacity, 4000-8000 cars per
hour would fall way short of a train. Given that we have to account for
pedestrians, cyclists, etc., I can easily see traffic lights continuing to
exist, making self driving cars not achieve the miracles people expect.

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jerf
It's just too far ahead of its time. You need to be able to do this without
building special infrastructure for the pods, which is an enormous risky up-
front investment for something that is, frankly, almost certain to fail. Times
will change and the infrastructure can't change with it. And you can't roll
the system out a little bit and get a little bit of the benefits; it's useless
until you fully cover a significant set of use cases.

By contrast, if the pods were self-driving cars on the roads that already
exist, the economics change completely. No special infrastructure. Can easily
roll out on a small scale for small benefits. Can easily ramp up. Massively
smaller initial outlay. System can grow and pay for itself as it goes.

~~~
rm_-rf_slash
The problem with self-driving cars as a cure-all is the Jevon's Paradox: if
the costs of auto transport are knocked down, then everyone will use them at
the slightest whim, especially when tired or drunk. People can live 2+ hours
away from work and it won't be a problem when they can work or sleep in their
car.

I'm not saying this will happen but I do fear that mobile homes will make a
comeback as people live permanently on the road in cars they don't have to
drive or pay property taxes for, all while taking up 2-3x the space of a
regular car.

~~~
jerf
In terms of getting a system like this set up, you seem to be complaining that
it might succeed too much. Perhaps so, but that's a problem the inventor here
would prefer to have rather than the one he has now.

Also, if that did happen, the RV might take up 2-3x the space of a car _while
moving_ , but then they end up not taking up the space of a _house_ while
stationary, which they usually are, so, you know, probably a net win for
density. On the off chance this took off bigtime the economy would further
adjust (rentable spots, etc.).

~~~
rm_-rf_slash
Let's put it this way: we had te technology for basic solar energy in the 19th
century. If we had forbidden fossil fuels and exclusively used solar and other
renewables like hydro, we would have taken a much longer time to get where we
are today, but the environment would have benefited and we wouldn't be in such
trouble with climate change. The path we choose is just that: a choice. And
cheap choices are easier.

I'm all for innovation, but one of the most laughable human qualities is the
idea that there will ever be a solution to a problem that makes the problem go
away. Ex: We may have eliminated smallpox but if it ever came back we'd be in
serious trouble.

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jpollock
This type of system would seem to have the same failure modes that complex
baggage handling systems have. [1]

They are both moving baggage (passengers) on demand between two points. I seem
to remember seeing an article indicating that the failures Denver was having
(all the empty pods end up at one spot) was visible in experiment, but I can't
find it now.

[1]
[http://www5.in.tum.de/~huckle/DIABaggage.pdf](http://www5.in.tum.de/~huckle/DIABaggage.pdf)
[2] [http://cdn.intechopen.com/pdfs-
wm/630.pdf](http://cdn.intechopen.com/pdfs-wm/630.pdf)

~~~
jpollock
Found the article discussing a simulation:

[http://collaboration.cmc.ec.gc.ca/science/rpn/biblio/ddj/Web...](http://collaboration.cmc.ec.gc.ca/science/rpn/biblio/ddj/Website/articles/DDJ/1997/9701/9701h/9701h.htm#rf1)

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listic
London Heathrow Airport has Travel Pods like that:
[https://youtu.be/F5Knmgr2Ge8](https://youtu.be/F5Knmgr2Ge8)

Wikipedia article lists five operational systems like this in the world:
[https://en.wikipedia.org/wiki/Personal_rapid_transit#List_of...](https://en.wikipedia.org/wiki/Personal_rapid_transit#List_of_operational_ATN_systems)

~~~
7952
Wow that's really cool. Now if they can just remove the silly cars and let me
ride my bike on it.

------
rch
I'm surprised ULTra wasn't mentioned:

[https://en.wikipedia.org/wiki/ULTra_(rapid_transit)](https://en.wikipedia.org/wiki/ULTra_\(rapid_transit\))

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fit2rule
What I sometimes wonder about is whether or not we'll some day seen these kind
of personal pods configured for use on existing railway stock. Many times
while waiting for a train, I've sat there pondering - "what if I could build
some sort of portable segway-like thing that I could just clamp onto one of
those rails on the track, step onto it, and propel myself down the line" ..
and I honestly can't think of any major reasons why this wouldn't be viable in
this day and age. Pods could clamp onto the existing rail, shuttle individuals
around, communicate with each other to avoid collisions, and so on .. maybe
I'm just not thinking it through well enough, but couldn't we just build
better rail-transport devices at the personal level which utilize the existing
infrastructure, instead of having to rebuild it all from scratch with
incompatible systems?

Something like this, only better:

[https://www.youtube.com/watch?v=8YVVSzS3Fco](https://www.youtube.com/watch?v=8YVVSzS3Fco)

~~~
jchoong
+1. Having something that can use the existing rail infrastructure in off
periods would be great as a transitional adoption method. That way you have
time to address the institutional jitters while still providing/proving real
service.

For example, during weekends / night when the load is much lower (or service
doesn't run anyway).

~~~
fit2rule
There is a lot of 'dead rail' out there that might be repurposed for this ..

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joe_the_user
This sort of thing was tried and apparent failed in the planned "ecotopia" of
Masdar City.

 _" The initial design banned automobiles, as travel will be accomplished via
public mass transit and personal rapid transit (PRT) systems, with existing
road and railways connecting to other locations outside the city..."_

But _" Under a revised design, public transport within the city will rely on
methods other than the PRTs."_

Reference:
[https://en.wikipedia.org/wiki/Masdar_City#Transport_system](https://en.wikipedia.org/wiki/Masdar_City#Transport_system)

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JDDunn9
I don't think you can argue that self-driving cars killed PRT, when we are
still building brand new subways and light rail.

I think anything new/innovative loses in the sound byte war. I remember ~2
years ago, the election for mayor of Honolulu hinged on the candidates'
stances on building a railroad vs. expanding the existing bus system (rail
won). I think if either of them were arguing for PRT, you couldn't explain it
to voters in the sound bytes summaries the news gives us.

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beefman
Didn't Aaron Patzer explain this, back when he concluded that Swift PRT
wouldn't work?

[https://web.archive.org/web/20140723180502/http://swiftprt.c...](https://web.archive.org/web/20140723180502/http://swiftprt.com/blog/2011/12/the-
future-of-ground-based-transportation-systems/)

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jchoong
This has a great (and updated) set of links for all PRT efforts
[http://faculty.washington.edu/jbs/itrans/prtquick.htm](http://faculty.washington.edu/jbs/itrans/prtquick.htm)

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peter303
I would think tracked PRTs would need less road space than driven cars. In
medium density cities roads are a quarter of square footage. You could
probably take out 1/2 or 2/3rds existing roads then and convert them to yards
or parks.

~~~
listic
I am afraid PRTs would have hard time competing with roads, and even more so
with railways, in terms of passenger carrying capacity.

Wikipedia says [1] high capacity road can carry 2,400 passengers per hour;
light rail 20,000 - 25,000 passengers per hour per lane in each direction.

[1]
[https://en.wikipedia.org/wiki/Light_rail#Comparison_with_hig...](https://en.wikipedia.org/wiki/Light_rail#Comparison_with_high_capacity_roads)

