In my quest to understand the growth of OSM, I had a little fun today.
I took the 1/1/2017 full history dump for Brussels and I extracted a shapefile with all the versions of all the highway=* that ever existed.
Then I wanted to visualize it to see if there was a pattern in how the roads get mapped: "first real roads, then paths" or "everything all the time". So I styled the paths clear green, the roads thin black and used a gray background for the current highways. Then I rendered a slide for every month.
It looks really cool, because it doesn't just show the chaos of our growth. As the black roads are drawn slightly transparent and the monthly slide shows every version of the road in that month, "active areas" show up in heavy black. I think it's really pretty.
On the occasion that it was a featured image in the Weekly OSM, I made a new version without a gray background and with a more logical image size.