Google's displayed traffic information for major interstates and freeways for years, but starting today, the popular web-based mapping application adds traffic conditions for arterial roads—that is, heavily trafficked roads. Even better: It works with Google Maps on your cellphone.


Google Maps traffic information Google Maps has just rolled out an exciting new traffic feature, that provides traffic data for… Read more

(Click the image above for a closer look.)

In fact, it not only displays traffic overlays for major roads on a GPS-enabled Google Maps for mobile; if you've got Google Maps with My Location enabled, Google crowdsources your data:

When you choose to enable Google Maps with My Location, your phone sends anonymous bits of data back to Google describing how fast you're moving. When we combine your speed with the speed of other phones on the road, across thousands of phones moving around a city at any given time, we can get a pretty good picture of live traffic conditions. We continuously combine this data and send it back to you for free in the Google Maps traffic layers. It takes almost zero effort on your part - just turn on Google Maps for mobile before starting your car - and the more people that participate, the better the resulting traffic reports get for everybody.


This is a fantastic feature (assuming you don't mind the anonymous usage statistics going to Google), and one that's actually available in some GPS devices already. The drawback on some devices—the iPhone, for example—is that you'd need to use Google Maps in place of another GPS application, and since the iPhone now features turn-by-turn GPS navigation applications, it's a bit of a sacrifice. Still, if Google were to go the extra mile and turn Google Maps into a turn-by-turn GPS app (something that seems well within reason, considering how much map data they've already got), then they'd really be on to something that a lot of us would potentially use.

To display traffic overlays on a map (where available), simply click the Traffic button in the top right of Google Maps in your browser or find the Traffic toggle on your cellphone (on the iPhone, you've got a Show/Hide Traffic toggle when you tap the button in the bottom right corner).

Traffic information here in Los Angeles appears to cover most major roads, and though I haven't road-tested against what the traffic data shows, it looks about right for what I'd expect this time of day. If you give it a try, let's hear how accurate it seems for your daily commute in the comments.

Arterial traffic available on Google Maps [Google LatLong]

The bright side of sitting in traffic: Crowdsourcing road congestion data [Official Google Blog]