The tiles are based on the Google Maps flat rectangular (Mercator) view of the Earth at the zoom level 14. Because of the rectangular view, tiles closer to the poles are actually smaller than those closer to the equator, but on average each tile is approximately 1-mile square and there are almost 276 million of them.
Each tile that has been visited by a VeloViewer users with a publicly viewable activity is displayed in this “heat” map. The number of visits and the number of visiting athletes is shown for each tile. Individual athletes or activities cannot be viewed. You can use the map to determine popular, unpopular tiles, or unvisited tiles (at least, not by anyone publicly claiming a visit).
Due to certain restrictions (aka GDPR) we can only show members of the public three levels on the heat map, with the data grouped into the three categories.
If you log in to your VeloViewer account you can also view your personal heat map, which only you can see, and which includes activities you have flagged as private. This data has nine levels to show greater detail than the public visits.
If you’ve done some exploration in places other athletes have not been, you may wish to claim some bragging rights by changing your activity to be publicly viewable (though if you do, it may take 24 hours for this to be visible as the data is cached).
If you are a logged in VeloViewer user with a premium Strava account there are nine categories for the public data, allowing the “heat” in the map to stand out better. Also, as you scroll around the map the scale will alter to accommodate more popular areas and the map is re-coloured accordingly. If you pan to areas much less popular you can use the “reset” button to limit the scale and map colours to only the tiles that are visible. This allows you to bring out the heat in any area.
Finally, due to the large number of tiles which make up the planet (did we say there are almost 276 million of them?) they can’t all be displayed at once, otherwise your computer might melt. If you zoom out too far on the map the tiles will be hidden. Zoom in to view the tiles or use the “Reset zoom” button on the bottom right of the map.