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A Twitter Data Scientist Hacks San Francisco's Subway Fares

fastcoexist.com

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Re: A Twitter Data Scientist Hacks San Francisco's Subway Fares

#4

Post by feralmoan »

nchuhoai wrote: post #2

I like the technical ingenuity, but do we really need to hack this system? I'm not debating the legitimacy of BART's cash flows, but IMO, the distance based system is the fairest system I can think of, closely correlating usage of resources with payments

It assumes that everyone has the same starting balance also, so the most efficient would be a crosspairing of commuters within the turnstiles at each destination. Way too complicated but maybe a fun thought experiment.

Re: A Twitter Data Scientist Hacks San Francisco's Subway Fares

#7

Post by ealdent »

nchuhoai wrote: post #2

I like the technical ingenuity, but do we really need to hack this system? I'm not debating the legitimacy of BART's cash flows, but IMO, the distance based system is the fairest system I can think of, closely correlating usage of resources with payments

There isn't even much technical ingenuity here. I'm not sure how this is even noteworthy. You save $1 between two people? So you split it for a lousy $0.50 or maybe $100 per year? Just stop drinking lattes and you'll save that in a month.

Not to mention if you live further away, you deserve to pay more to make up for the extra resources needed to move you around, as nchuhoai said.

Re: A Twitter Data Scientist Hacks San Francisco's Subway Fares

#8

Post by GuiA »

When I first moved to SF as a poor grad student doing a summer internship, your Clipper card could go in the negative (for example if you had $2 on it and took a $5 route, you'd be at -$3). Getting a new Clipper card was only something like $1.50; if you took the Caltrain/BART often (expensive routes), it'd almost always be advantageous to buy a clipper card with as little cash on it as possible, toss your card away when it was in the negative and just buy a new one every time.

I wish Fast Company had written an article about me at the time :( (and this was "legal" too, whereas the technique described in the article is illegal since you're not allowed to transfer payment titles, per BART's/Muni's policies)

(I believe you can't do that anymore - that the maximum negative balance that you can get to is now the same as the price of a new Clipper card)

Re: A Twitter Data Scientist Hacks San Francisco's Subway Fares

#9

Post by krallja »

The two passengers are going in opposite directions, so when would they ever have a chance to switch passes?

Are they supposed to get off their trains and meet each other on the platform, then wait for another train? Sounds like a stupid amount of work to steal 85 cents.

Re: A Twitter Data Scientist Hacks San Francisco's Subway Fares

#10

Post by jaredsohn »

nchuhoai wrote: post #2

I like the technical ingenuity, but do we really need to hack this system? I'm not debating the legitimacy of BART's cash flows, but IMO, the distance based system is the fairest system I can think of, closely correlating usage of resources with payments

Agreed. Also on the personal level, while it could save you some money, you're not only offsetting mass transit funds to the taxpayers (or other passengers), but also taking a risk that the card you are trading for is from where they say it was from and that it contains the amount of money the other person claimed.

You're also potentially (haven't thought through all of the details yet) losing out on the convenience to tie your Clipper card with your credit card, take advantage of BART high value cards ($64 value for $60), and being able to take advantage of paying for transit in pre-tax dollars.

And unless this could be made very simple, you're going through a lot of daily stress just to save a very small amount of money which can distract you from doing things that give you more value.

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