I noticed in the global heatmap in new york city, if you set the sports to “all sports” there weird squares all over the place. they are especially prominent if you set it specifically to “all cycle sports” or just “ride” only. 

they are perfectly north-south oriented, and are 0.25x0.25 miles (or 1 mile in circumference)

it does not take much to tell that there are no such routes that exist in the city. so what causes these? I’m also wondering if it’s just on my side..