[alexkus]

Can't remember the terminology they use but Strava allows you to define privacy areas (within a configurable radius of a point) where no points are shown on your individual routes. Exactly to stop someone working out where you live/work from browsing your history.

Either they haven't honoured this when calculating the global heatmap or, more likely (and harder to fix), such locations are given away by friends uploads (who don't have the same privacy areas defined).

Oops.

[paulmach]

On this map I took out any point within 1km of the start or end of every ride. This is stronger than what users have set and eliminates 1000s of "hot spot".

I've looked into a couple of these cases and it's friends "coming by for a ride" or them stopping at their house mid ride.

I'm working on further eliminating these points by just not included "stopped" points. I've also tried doing some image processing to remove these hot spots but have had mixed results.

[madeofpalk]

There's some similar interesting artefacts in Sydney of very narrow red 'streaks' that look to be between 10 to 40 metres long.

http://labs.strava.com/heatmap/#17/-208.78860/-33.89894/gray...

Any idea what these are? I've only seen them in the bike layer

Edit: I found more in a university http://labs.strava.com/heatmap/#17/-208.81832/-33.88863/gray...

[mxfh]

Found a lot of residential building footprints with activity inside just browsing around at z17. Maybe you could use slide to check local activity hotspot's and cross reference them against OSM building footprints or remove those gravity spots with no uniform direction or evenly weighted exit path slope altogether.

Another approach might be only displaying common paths of 2 or more unique client id's.

[alexkus]

Thanks for the clarification. I know Strava takes the issue of privacy seriously!