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Get in touch with technology with Tech Stuff from www.HowStuffWorks.com.

Chris Pollette

Hello again, everyone. Welcome to Tech Stuff. My name is Chris Pollette, and I am an editor at www.HowStuffWorks.com. Sitting across from me as usual is senior writer, Jonathan Strickland.

Jonathan Strickland

And Leon is getting larger.

Chris Pollette

You’ve been threatening to do that for a while now, haven’t you?

Jonathan Strickland

Yes, I have. Today’s episode comes to us courtesy of a little listener mail. This listener mail comes from John. John says, “Hi, guys. I hope this email goes through. I didn’t see a contact email on your web page, but I always hear you announce it at the end of your podcasts.” It got through, John.

“First of all, I love listening to your podcast. You guys are great, and the subjects you discuss are also. Keep up the good work. My question is in regards to Google Maps traffic overlay. I usually check it before I leave from work in case I have to take an alternate route due to traffic problems.

“I’m wondering how Google can display how the relative speed is of a particular stretch of highway or road. Do they use cameras? Do they measure cell towers handing off phones? Do they rely on people calling in? Google seems to have a lot of public information gathered in one place, but I don’t know how they got their real-time traffic data.

“If you’ve already done an article or podcast on this that I’ve missed, please direct me in the right direction. It would be great to hear an answer on the podcast, of course. I am really interested in the answer, so any way you can help would be appreciated. Keep up the great work. John.”

Thanks, John.

Chris Pollette

You want to know the fascinating thing about that, John? They’re getting it from you.

Jonathan Strickland

If you’re using any kind of cell phone that happens to have a GPS receiver in it and also is using Google Maps with the My Location option turned on, you are contributing to the information that Google is using to generate those traffic overlays.

Chris Pollette

That’s pretty cool. Well, it depends on how you look at it. You might be afraid, for example, that, “Wait a minute. So I have Google Maps for mobile turned on on my phone. I thought I was just checking out the traffic. You mean they’re taking information from me?”

Google would actually say not to worry too much about that because they’re not really taking any identifiable information from you. However, they are also taking pains to mix it in with other information taken from other customers, so don’t worry so much. You’re not being peeped upon, and they aren’t following you on your way to work. Probably.