With Subway in the Sky, Valley Meets Plateau | Hacker News Reader

With Subway in the Sky, Valley Meets Plateau

nytimes.com

39 pointsyetanotherone10 comments

I saw an interesting TEDx presentation by Jared Ficklin pertaining to gondola systems as mass transit in a cit and how to get the American public to buy into it[0].

[0] https://www.youtube.com/watch?v=FoQmgSOB9n0

This proposal was for a way to solve Austin's traffic problems. Given the geography around here (hills, lakes, NIMBYs), I think it's a plausible solution. But it looks like the city council is going to put streetcars (urban rail) on the ballot at a starting cost of $600 million.

He gave the presentation in Kansas City during a big push for streetcars. The streetcars are happening, and as far as I know the people in charge didn't give any attention to the gondola solution. I live outside of the city proper, so I haven't been following it too closely, but I do know that the streetcar is very expensive and that votes for expansion have already failed.

How does the cost of this compare to elevated rail? Here in Miami we have a very very limited 2 line elevated rail [0] that the estimates to expand it run in the tens of billions of $. The idea of building retail into the parking garage structure/stations is intriguing as it could get private developers to underwrite the costs.

My other question would be (since I'm thinking Miami here), how would these cable systems fare against hurricanes? I assume the cars would just be docked in a safe building (parking garage structure).

[0] http://en.wikipedia.org/wiki/Metrorail_(Miami)

Elevated rail, even monorail, is considerably more expensive, but also provides far higher capacity. You can also increase capacity on a train line relatively easily with shorter intervals and longer trains, while a gondola's carrying capacity is essentially fixed.

Rough comparison between three recent 3rd-world systems:

- La Paz gondola: 3000 passengers per hour per direction (pphpd), ~$10m/km

- Mumbai Monorail: 10,000 pphpd, ~$20m/km

- BTS Skytrain, Bangkok: >30,000 pphpd, >$100m/km (on recent extensions)

Gondolas make sense in hilly locales where hurricanes are not a threat (like La Paz), they'd be a non-starter for both reasons in Miami.

I'm pretty sure a gondola can hold its own in a hurricane (as long as it isn't running). Most urban systems use the same technology as alpine systems, which have to withstand harsh blizzards.

Similar Aerial tramway are deployed in Algeria , where they are used as a transport cars and not as a tourist cars, the system is quite useful, each year it transport more than a million passenger. http://gondolaproject.com/category/installations/algerian-go... http://www.strmtg.developpement-durable.gouv.fr/IMG/pdf/cabl...

Check out Nick Chu's blog, the Gondola Project [0], where he's been documenting urban gondolas around the world for years.

Like La Paz, mountainous Medellin, Colombia has been building a system of gondolas [1], the first line of which opened in 2004. There's a $500 million system under construction in Lagos, Nigeria. And there are many smaller projects getting started elsewhere, including possibly in Hamburg, Germany, where voters will decide this week whether to fund a cable car over the Elbe.

0. http://gondolaproject.com

1. https://en.wikipedia.org/w/index.php?title=Metrocable_%28Med...

Caracas and Rio, too.

This is pretty fascinating (though my fear of heights would not make me a happy rider of these).

But the title really really bugs me. Subway in the sky? Do we call tramways subways on the ground?

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