The London Underground map is right up there with the Mercator projection in the cartographic pantheon. Designer Harry Beck replaced assumptions of geographic accuracy with principles of electrical wiring diagrams to create an entirely new way of thinking about urban wayfinding. But that was nearly a century ago. According to research by NYU professor Zhan Gao, 30% of travelers choose the wrong route on the current London Tube map, which has twice as many transit lines and is just as likely to be squinted at on a smartphone as gazed at on a wall. Is it time for an update?