Greg Miller, a 37-year-old software engineer in Astoria, Queens, is walking every street in every borough of New York City—8,000 miles. He started in the pandemic and has already done 2,400 miles. He is part of a subreddit of like-minded perambulators: /r/EveryBlockNYC

I walk 3.2 miles daily, almost always with the dog, and on weekends I often use the Footpath app to plot a fresh course through nearby streets, favoring streets we haven’t been on before. Miller is orders of magnitude more methodical than I am.