Physical Opt-Out
Tuesday, Jun 17, 2003
I got a really interesting piece of mail the other day, offering a kind of opt-out I hadn't seen before.

Though I've been in Pittsburgh for the last year, I still have my FasTrak transponder to pay my Bay Area bridge tolls, and so they still send me monthly statements, politely informing me that I haven't actually crossed any SF bridges since the last statement. This time though, they wrote to tell me about a new service that I'd be helping build, just by driving around., run by the Metropolitan Transportation Commission, is a realtime traffic information aggregator, to help drivers estimate how long a given trip will take, accounting for realtime traffic conditions.

The idea isn't new. Seattle has a similar system, that uses inductive loops built in to the highway to measure traffic speeds, and facilitates some nifty gadgets for using that information. The Bay Area currently uses a system of video cameras, along with some very slick computer vision software (nifty video) developed by my former artificial intelligence professor at Berkeley, to video a stretch of highway, count the cars that pass by, and measure their speed. Nevertheless, I'm guessing FasTrak readers are cheap, and allow for unique identification of cars, so you can put up more datapoints quickly and easily (build them into the overpasses, probably) and understand not just how fast traffic is moving at a given point, but know how fast it's moving between those points, since you know how long it takes a particular vehicle to go from point A to point B.

As I was reading this, thinking "nifty!" I noticed the static-proof bag that came along with the letter. At first I assumed it was for sending my current transponder back to trade in for a new one, better equipped to work with their system (a traditional 'opt-in' service). As I read on, understanding that I didn't have to do anything for the system to work, I thought it was for sending my transponder back if I wanted one that wouldn't work with their tracking system, and would only pay tolls (a traditional 'opt-out' system).

Despite their absolute assurance that "no personal information will be collected or stored," and that they will "never know the location of any particular vehicle or person" or "collect information on individual driving patterns" I understand that many people value their privacy too much. After all, nothing in those platitudes prevents the highway patrol from knowing that there are one or more vehicles traveling above the speed limit, and where they are, so they could then be found and identified.

Still, as much as I value the concept of privacy, I personally don't care about whether they can see how fast I'm going, and I'm trusting (as I am with TiVo) that it won't turn out badly.

So what about the anti-static bag? "If you prefer not to participate in this program, but still want the convenience of using FasTrak, place your toll tag in the enclosed Mylar bag after you have passed through the toll plaza; then it cannot be detected by the roadside readers. To function at the toll plazas, the toll tag must be removed from the Mylar bag." Thus it's an 'opt-out' system, but of a physical nature. at least when you're opting out, you know you're actually opting out, and aren't just trusting the service to respect your wishes (unless the bag's a fake, of course).

It's like the Hokey-Pokey. Opt-in, Opt-out, Opt-in, then out. that's what it's all about!

If you like it, please share it.

Hi, I'm Kevin Fox.
I've been blogging at since 1998.
I can be reached at .

I also have a resume.


I'm co-founder in
a fantastic startup fulfilling the promise of the Internet of Things.

The Imp is a computer and wi-fi connection smaller and cheaper than a memory card.

Find out more.

We're also hiring.


I post most frequently on Twitter as @kfury and on Google Plus.


I've led design at Mozilla Labs, designed Gmail 1.0, Google Reader 2.0, FriendFeed, and a few special projects at Facebook.

©2012 Kevin Fox