March 30, 2012

Traffic congestion and data science

Recently, I mentioned the possibility of using bus timing data to probe congestion on Auckland roads.  This idea has been bypassed by Google, who now provide real-time congestion maps of New Zealand using smartphone location data.

If you run Google Maps or Google Navigation, you have the option of sending anonymous GPS-based location data to Google, so they know the locations of lots of phones.  By tracking the speed of phones that are moving along roads, they can work out the traffic speed, and measure congestion.   This is harder than it sounds — GPS accuracy on its own is not enough to distinguish phones in cars from phones carried by pedestrians — but using combined location and speed data they can even give separate congestion information in each direction on many roads.

For example, if you were coming to our public lecture on Tuesday, you might look on Google Maps and click on the “Traffic” label, and see that Symonds St is totally clogged, and decide to come up Grafton Rd instead.

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Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »