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Transportation Math

Taxis By Algorithm: Streamlining City Transport With Graph Theory 72

Posted by timothy from the upsetting-the-big-apple-cartel dept.
New submitter Mark Buchanan (3595113) writes with a story about research from scientists at MIT, Cornell and elsewhere showing "that big city taxi systems could be made 40% more efficient with device-enabled taxi sharing. We could cut miles driven, costs, and pollution with the right application of just data and algorithms, and do it while introducing no more than a 5 minute delay to any person's trip. " Letting such algorithms compete seems an excellent reason to encourage, rather than reject by law, ride-coordination services like Uber and Lyft.
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Taxis By Algorithm: Streamlining City Transport With Graph Theory More

Taxis By Algorithm: Streamlining City Transport With Graph Theory

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  • Actually (Score:2, Insightful)

    by Anonymous Coward

    I don't want to share my cab.

    • Re: (Score:3, Insightful)

      by SpankiMonki ( 3493987 )

      I don't want to share my cab.

      ...and it's unlikely you'll want to wait an *extra* 5-10 minutes to get where you're going either - especially if you're a Manhattanite. Further, if you live in Manhattan and are concerned about the cost of riding in a taxi, there's this thing they have there...what's it called...oh yeah, the subway.

      • Yeah, on the face of it, this really doesn't seem to make much sense. Taxis are a luxury. The whole point of them is you can jump in one at a moment's notice, and it'll take you wherever you want to go, with no delay other than that imposed by traffic. They're not cheap. If you want cheap and slow, that's what the subway and buses are for, or you can just walk.

        • Re:Actually (Score:4, Insightful)

          by mrchaotica ( 681592 ) * on Thursday March 27, 2014 @12:27PM (#46593623)

          And what makes you so certain there's not a market for a service halfway between taxis and buses/subway?

          • That's easy: the taxi companies don't want it. Sounds like you're proposing two classes of taxis; the regular ones we have now, and a cheaper version (perhaps painted green instead of yellow) where you have to share rides with other passengers, wait longer, etc. The short answer is: that can't be done. It's totally impossible. The existing taxi companies wouldn't want this, that's why.

            • Taxi companies are not the ones that will implement something like this. The disruptive system will be fleets of self-driving vehicles ranging from small cars up to minibusses, where you'll specify your journey on a smartphone and get a range of quotes based on how much slack you're willing to have in your schedule and how many people you're willing to share with, ranging from close to the price of a taxi to close to the price of a bus.

              • Taxi companies won't allow self-driving vehicles in NYC. It doesn't matter who wants to implement it. To get a license in NYC to operate a taxi costs a fortune, and the taxi companies would not allow any competition from such a system. It's simply going to be illegal to implement a system like what you describe.

                • A well regulated market, that ends up serving only those regulated, and not the customers, or anyone else for that matter. And liberals love regulated markets and think that there is nothing wrong with over-regulation.

                  Well, here is a GREAT example or the wonderfulness of REGULATION.

                  Nothing will change, because the status quo forbids it. And that is itself a problem

                  • This isn't regulation, it's corruption. It's a common feature of crappy, third-world countries. Well-run countries don't have this problem so much. You wouldn't see this in liberal, high quality-of-life index countries like Switzerland.

                    • It is regulation, the corrupt part is called regulatory capture. But this is what happens, incumbents like regulation, because it raises the cost of entry for new opperators.

                      The other this you don't see in Switzerland is tipping at a guess also. sigh.

                  • And liberals love regulated markets and think that there is nothing wrong with over-regulation.

                    Damn those liberals! They want to destroy Tesla...oh, wait.

                    You keep using that word. I don't think it means what you think it means.

          • Re: (Score:2)

            by mikael ( 484 )

            San Francisco International airport has shuttle buses - tell them where you want to go, and they would dynamically create a route that went through all destinations. Other cities offer shuttle buses booked in advance - tell them where you want to be picked up, and where you want to go, and they would dynamically create a route.

            Some taxi services would allow multiple drop-off points. It was up to the customers to decide how the each segment of the route should be paid.

      • Re: (Score:2)

        by njnnja ( 2833511 )

        I don't think they are saying that the typical user will experience a 5 minute longer delay; rather, the typical user will experience a shorter wait time. If the entire system is 40% more efficient, then even if you have to wait a little longer because the cab goes a little out of your way, that should be offset by a lower wait time. *Some* users will experience higher wait + travel times, but as they say here, no more than a few minutes.

        The reason that they bring it up is because there are certain kinds

    • Don't worry, taxi companies don't want you to share your cab either so this simply is not going to happen short of governmental decree. There may be one of those marketing stunts where they say they are using the tech but really are not upon investigation as is typical of such things.

      So don't worry, your selfish need to waste energy and produce as many emissions as you can in the pursuit of laziness and personal comfort is safe!

      Capitalism for the win!

    • You've sort of hit on the problem and solution. What we need is something that is not called a "taxi" for this. Rather than taking the existing taxi system and adding ride sharing, we should supplement taxis with a new form of public transport based on this system. The new system would be somewhere between a bus and a taxi- a medium sized public vehicle (perhaps "minibus" size), but which would be summoned on demand and travel to your chosen destination like a taxi rather than travelling a fixed schedule li

    • Cool, then you can pay extra for the privilege! :)

  • Taxi licensing laws aren't about good service. (Score:5, Insightful)

    by Ungrounded Lightning ( 62228 ) on Thursday March 27, 2014 @11:10AM (#46592915) Journal

    Letting such agorithms compete seems an excellent reason to encourage, rather than reject by law, ride-coordination services like Uber and Lyft.

    Taxi licensing laws aren't about giving the CUSTOMERS good service. They're about limiting competition so the licensed cab owners have a regulated oligopoly that limits competition and keeps the prices higher than market-clearing.

    It's much like the laws limiting car sales to dealers that are giving Tesla such a problem.

    This is crony capitalism at its most blatant.

    • Re: (Score:2, Interesting)

      by Anonymous Coward

      yes and no.

      Your claim is likely partially true. However, another reason for licensing laws is to reduce the amount of traffic on the road. More taxis on the road can mean more traffic congestion http://blogs.reuters.com/great-debate/2012/01/20/more-taxis-mean-more-traffic/.

    • Re: (Score:1)

      by AvitarX ( 172628 )

      Aren't the prices set by law too?

      Cabs are regulated similar to the post-office, there are more and less profitable routes, and some subsidize others.

      They don't want non-licensed services that can charge whatever they want to snipe profitable routes at a lower rate.

      I'm not saying it's good, but it's really not a case of artificial scarcity. I know I've gone on routes that are higher than they like, and others where they'd be happy to negotiate a lower price.

      • Aren't the prices set by law too?

        The point is that they are set higher than a free market would provide.

        Cabs are regulated similar to the post-office, there are more and less profitable routes, and some subsidize others.

        Which is, of course, idiotic. There is no reason for routes to "cost the same". Should the government also regulate grocery stores so that oatmeal is the same price as filet mignon? That way all meals will cost the same.

        They don't want non-licensed services that can charge whatever they want to snipe profitable routes at a lower rate.

        You cannot repeal the laws of supply and demand. If you fix the price of bread, you get empty shelves. If you fix the price of taxi fares, you will have plenty of cabs lining up for the profitable routes, and no one

    • There is a case (Score:2, Insightful)

      by brunes69 ( 86786 )

      There is a case to be made for taxi regulation. It protects passengers, which is really the main reason taxi regulation exists. In order to fund that regulation, they allow companies artificial monopolies.

      The last thing you want is a totally unregulated taxi industry. There is a reason these kinds of things became regulated in the first place.

  • And making a big city taxi system more efficient helps the existing taxi companies how?

    • This can reduce waiting times in "taxi rush hour" - would you prefer to wait 15 minutes for "your own" taxi, or share one that comes in 5 minute?
      Also, if the cab carries two different passengers, cab drivers get payment from each.
      In Athens, Greece, the cabs that carry one passenger might stop and take another one that goes in the same direction (and get full payment from one passenger and partial or full payment from the other). It helps a lot with the "I can't find a cab at this time"

      • Re:The "level playing field" taxi companies demand (Score:5, Insightful)

        by timeOday ( 582209 ) on Thursday March 27, 2014 @12:51PM (#46593851)

        This can reduce waiting times in "taxi rush hour" - would you prefer to wait 15 minutes for "your own" taxi, or share one that comes in 5 minute?

        It's a Prisoner's Dilemma situation. If everybody were willing to wait the 5 minutes, that would be better for everybody. But the ideal situation for an individual is if everybody else shares while they themselves do not, thus avoiding even the 5 minute wait. Each person acting in their best interest individually leads to a poor outcome for everybody.

        The bus is the same. If everybody decided (at once) to start riding the bus, it would be faster than everybody driving cars because there would be so little congestion on the streets, and so many bus routes. But since only a few people take the bus, the busses slog thorough the congestion, AND (being busses) have to stop all the time. So the situation persists.

        • The bus is the same. If everybody decided (at once) to start riding the bus, it would be faster than everybody driving cars because there would be so little congestion on the streets, and so many bus routes. But since only a few people take the bus, the busses slog thorough the congestion, AND (being busses) have to stop all the time. So the situation persists.

          But if everybody started taking the bus, the stops would be more frequent and longer. The congestion might be better, but your overall trip length might still be long due to all of the stopping that the bus has to do.

        • But like the bus system, there should be 'pricing' system that can make it work for all. I.e. taxi operators makes more (drive more ppl per trip), there's increase in wait time for people but the cost should be cheaper than before, and for people who doesn't want to share, well, higher price.

      • Also, if the cab carries two different passengers, cab drivers get payment from each.

        Changing this, maybe so that each passenger only pays 75% or whatever, would fix the urge to have their own taxi. Saving ~$10 can do that.

      • Yep. I think as other people have pointed out, solving these problems always depends upon thinking about the context, the benefits and the costs involved.

        In situations where people are a lot of people are waiting for not many taxis—like the airport—sharing doesn't just mean a cost incentive but a time incentive too. Sharing in these situations is beneficial to both passengers and taxis, who spend less time waiting in long lines, and it benefits the transportation hub and the city as a whole.

    • less wasted time and fuel on empty cabs...

  • [I was beaten to this by an AC, but since many filter AC comments I'll jump in...] The Taxi companies have no interest in something that will effectively reduce their revenue.

    • Re: (Score:2)

      by fermion ( 181285 )
      the fallacy is comparing ride share services with Taxis. They are different. One is regulated service provided to make sure that public can be assured of a higher level of transportation than fixed rate public transport, the other is an ad hoc less regulated service akin to hiring a limo. I am sure no one here would make the argument that Uber is a ripoff because it costs more than a bus?

      There are two problem with the ride share services. First is liability. Those who provide the service are often d

  • "Dolmush" (Score:5, Interesting)

    by should_be_linear ( 779431 ) on Thursday March 27, 2014 @11:25AM (#46593029)
    In Turkey, I saw even better thing. Idea is this: public transport bus is too slow and awkward: stops are either sparse - lots of walking, or dense - making traveling too slow, and taxi for single person is too expensive (fuel + driver). In Turkey these is this "Dolmush" thing, which is mini-bus, that stops anywhere (like Taxi), costs fix rate (like public transport) and is just practical. It kicks ass of all other forms of public transport *AND* computerized car/taxi sharing.

    • I bet you a Dolmush guided by a computerized transportation-sharing network would be even more efficient and profitable.

    • Re: (Score:2)

      by Ichijo ( 607641 )
      According to the USA's National Transit Database, this kind of "demand response" system costs Los Angeles $7.83 per passenger mile [ntdprogram.gov], compared with $1.43 for buses and 42 cents for commuter buses. So it's very costly.

  • Sharing pilots in NYC (Score:5, Insightful)

    by clinko ( 232501 ) on Thursday March 27, 2014 @11:50AM (#46593261) Journal

    There was a pilot for this program 4 years ago in NYC:
    http://www.nytimes.com/2010/02... [nytimes.com]

    Also there was strike that mandated it 7 years ago for a few days.
    http://www.nytimes.com/2007/09... [nytimes.com]

    In short, no one liked it. If people wanted to have a delayed trip and people with them, they'd just take the Subway.

  • We have a dominant Taxi company in the city where I live, one so influential and powerful that it has landed a former city councilman in Federal court for accepting bribe money to stifle competition from other companies. They are, of course, bringing some serious legal pressure to bear on our politicians for allowing Uber to operate independent of codes regulating the taxi business. Seems that the biggest barriers to improving cab transportation are existing regulations and conflict with existing companies,

  • Problem is in New York... (Score:5, Interesting)

    by RevWaldo ( 1186281 ) on Thursday March 27, 2014 @12:26PM (#46593605)
    The law is a cab is legally bound to take you anywhere in the five boroughs, whether they want to or not. Of course, if you tell them where you want to go before you get in, there's not much you can do to force the issue, except maybe getting their plate number and report it, which you probably won't do anyway. So savvy NYers don't give up the destination until they're in the cab.

    Long story short, a system that requires you provide both the pickup AND arrival points will require some serious clampdowns to keep uptowners and outer-borough folk from being left out in the cold.

    .

  • Maximising the wrong thing? (Score:5, Interesting)

    by pr0nbot ( 313417 ) on Thursday March 27, 2014 @01:06PM (#46594013)

    As far as cabbies are concerned, the optimum algorithm will be whatever maximises their revenue. Any algorithm that doesn't will probably be vulnerable to cheating, i.e. a rogue cabbie that can make more money exploiting some aspect of the algorithm will do so.

  • I had a friend tell me about the time he filled in for a day as a dispatcher for a cab company. He said he tried to do it efficiently by looking at where the customer was and where the closest non-busy taxi was and sending that one. Turns our the taxi drivers didn't like it. They wanted him to send them out in order so they all got the same number of fares.

    • Split all the fairs evenly to all drivers - since fairs are decided by millage anyway it shouldn't be a big deal... unless they figure it out and realize fewer miles are being driven with a efficient system. If they don't charge for the distance to the pick up, then that factor would be a lower overhead cost and save them money.

      Tips. Well, that is not actually randomly distributed so I could see complaints about not getting more time around certain areas at certain times. They won't ever agree to pool tip

  • I'd extend this idea to all cars and traffic lights. If cars could talk to traffic lights and each other, that'd save tons of time, miles driven, costs, and pollution. Such a network can optimize car routes to choose less congested ones, recommend car speeds, and change traffic lights accordingly to provide green light corridors.

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