Mugged by reality

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For a particularly risible example of an economist planting his flag in neighbouring territory (in this case, traffic flow and operations research) without bothering to check what the locals think first, here’s a bright idea from Joshua Gans of Melbourne Business School:

Imagine also (and I know this might be a stretch) that we all entered our route plans into the iPhone and those plans were uploaded into the cloud. Then all of this information could be aggregated and the ‘optimal’ route for each of us worked out so that traffic was minimised. We would then receive directions based on the centrally coordinated route and all be better off for it…

Now you wouldn’t be compelled to follow the instructions handed to you but if it was meaningful you would follow them anyway as it will likely make you at least weakly better off by doing so. That is, the routes handed down could be incentive compatible and also update in real time as others came into and out of the mix.

(emphasis added)

That’s some algorithm! I trust Josh will leave the engineering up to someone else.

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3 Responses to “Mugged by reality”

  1. Dan Says:

    Perhaps the funniest thing about this idea is that it actually more-or-less exists already. If you google “iphone traffic info” you’ll see that the first result points you to the “show traffic” option on the iPhone’s google maps app, which comes inbuilt with the device. It highlights – in as close to real time as we’ll get for an iPhone – areas of congested traffic and areas of smooth driving on your map.

    So far from checking what the locals think, Josh has actually neglected to check if it more-or-less exists already.

    As an aside, what is much more likely (and useful) is that when we stop driving ourselves and let the computer take over (which is a when, not an if), that research currently being done (I think at MIT, can’t remember where I read the research) on ant group patterns of movement will be used navigate us and erase the possibility of traffic jams. Ants don’t get traffic jams – there is some crazy innate natural instinct that allows them to simply continue to move without stopping, regardless of how many there are in a bunch.

  2. kathi Says:

    i don’t understand why he would even need to come up with that “brilliant” idea (cos we really need less freedom of choice). surely the business world is plenty screwed up enough for him to be rather occupied with that for a while!

  3. Nick Says:

    Dan: To be fair, what Gans describes isn’t trivial, and isn’t equivalent to any known app. It’s known as a congestion game, where drivers are represented as vertices and roads as edges on a graph, and the assignment of traffic to various routes is modelled as network flow. The search procedure works by picking a route, then looking locally to find a better one until the optimal route is found, so that no driver would be better off switching to another path. In practice, for large numbers of roads/drivers, where each player has a different pair of startpoints and destinations, this may not be possible in polynomial time, and running time may increase exponentially with the number of drivers.

    Kathi: Apparently ‘freedom of choice’ adds about 33 percent to our daily travel time.

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