I was searching for a location this morning on Google Maps and I came across the “popular times” chart that many of you are probably familiar with. It shows you how busy the location you’re looking at tends to be throughout the day. But this time around, I noticed a pulsing “live” dot and it got me wondering: How live is live?

Google collects this data from of our phones.

It is aggregated and anonymized Location History data from anyone who has opted in on their Google Account. If you’re using Google Maps and have your location services set to “always”, you can actually see a timeline of the places you’ve visited — even if you haven’t explicitly navigated to them (see above).

So the short answer is that the live data is really live. If there’s a spike in the busyness of a particular venue — one that doesn’t match historical busyness patterns — the Google network can pick it up.

I’m fascinated by this kind of city data because I see it as part of the future of city building. Why not use more data to inform the way in which we plan and build our cities. Retail data, traffic data, migratory patterns, population densities — all of this and more is now available to us.