Map-making-guy Chris Whong set out to make a map of all the places in New York City that are "subway deserts," i.e. places that are more than 500 meters (about 0.3 miles) from the nearest subway station. To make the map, he put a blue dot with a 500-meter
diameter radius over every station. The parts that were left exposed are the deserts. Sure, it's a little difficult to read, but Whong makes his point, which is (presumably) that nobody wants to take the bus.