This blobby social lifesaver is an isochrone map: one that indicates not just the physical distance between places, but the amount of time it takes to get from one spot to another. When they were first introduced in the 19th century, individual isochrone maps tended to center on a particular place, and contained a set amount of information: one might tell you how many days’ journey it was from London to anywhere else in the world, while another showed how many hours it would take to get from the central train station in Melbourne, Australia, to a series of more remote stops.
Now, the increasing availability of geographical and transit-related data has led to an explosion in isochrone experiments. Whether you’re trying to shorten your commute, visualize transportation-related inequalities, or simply get coffee with someone who lives across the river, there’s probably a map for that.