Jul 31, 2009

Accuracy of Google Maps Traffic Reports

Recently, while driving back from Pennsylvania, we ran into some traffic on a highway. On a whim, I decided to take a look at what Google Maps had to say about it. Using the Google Maps mobile application for my Blackberry, I brought up the Traffic overlay.

Surprisingly enough, Google was providing traffic overlays far outside of the DC metro area. So, that got me thinking - how are they so 'real-time' with this. And yes, they were pretty accurate about the traffic situation that we were in.

Did some research today, and it looks like originally they were getting this data from a number of sources, including road sensors, commercial trucks using GPS, commercial car fleets using GPS which they were able to aggregate to see how traffic was flowing.

My guess, during my drive, was that they are probably tapping into thousands of cell phones for this information - not tapping into the phones, but at least following where the phones are. Google Latitude uses this technology of cell-tower triangulation to give you your own position to some degree of accuracy. So, it seems it would be easy enough to take that data and use it to get an idea of traffic flow - lot more cell phones out there as compared with commercial vehicles with GPS.

I saw this link, which validates my theory. Looks like Verizon is providing anonymized data to allow for more accurate calculations of traffic flow.

What do you think about this? I think it is ok, but it would be interesting to see what others think...