Bluetooth Guerilla Traffic Info

An idea I’ve run across frequently lately is that if you’ve got a potentially good, or at least interesting idea, there’s a lot of value in not hoarding it, but rather spreading it widely. Especially if you don’t foresee having the time or inclination to carry it to completion. It’s in this spirit that I begin this blog and post ideas.

The Transparent Society really changed how I think about the modern world and privacy. It seems that we now live in a world where privacy is disappearing, simply because the surveillance technology is so cheap, and it’s increasingly easy to search through logged data. If anything, what we can do is put the technology in the hands of the masses, rather than it being a tool of the politically privileged.

So, in that spirit, I was thinking one day, while contemplating my commute across San Francisco, that it would be nice to have detailed traffic data — not just the data on traffic flow on the major freeways that you can find on or, but data on many of the major San Francisco streets. And I thought, well, how would one do this cheaply.

And then I remembered when I went to see Survival Research Labs perform in downtown San Jose last year at the

ZeroOne San Jose thing. There were some exhibits sitting around as we formed a long line to get in, and I looked at a few of them. One which caught my eye was Set to Discoverable by Loca.

The way the regular highway traffic flow information works is via a sizable percentage of drivers who have the FasTrack RF transponders which enable paying tolls on the bridges without stopping. Each transponder has a unique serial number, you track when it passes one antenna and then when it passes another some distance later. With a lot of data points, you get some fairly accurate traffic flow data.

But, this is just like what a discoverable Bluetooth device can do! And a lot of people have them, with current generation mobile phones. Imagine a bunch of battery/solar powered boxes mounted around the city, using an 802.11b mesh network to communicate. The big hardware cost is in the number of boxes needed, not the cost of each box.

Of course, I would advocate an open hardware and software design with public access to all the data, not merely the aggregate traffic flow information. The essence of this “good” surveillance in my opinion is that it not be in the hands of a select class (e.g. law enforcement), but in everyone’s hands.

If this bothers you, consider setting your Bluetooth devices to not be discoverable. (I have.) And, for that matter, the Pandora’s box is already wide open — automated tracking of vehicles via license plates alone (cameras + OCR + computer database) is already possible. See Schneier on Security: Vehicle Tracking in the UK.

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