These actually point of a failure mode of the original topic's visualization, at least as it pertains to public transit: https://upload.wikimedia.org/wikipedia/

These actually point of a failure mode of the original topic's visualization, at least as it pertains to public transit: https://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Map_of_Melbourne_and_environs_minimum_railway_or_tramway_time_zones.jpg/1920px-Map_of_Melbourne_and_environs_minimum_railway_or_tramway_time_zones.jpg https://upload.wikimedia.org/wikipedia/commons/thumb/4/40/Ma... (I think a previous commenter called this out by referring to subways as "wormholes") As for car directions, you should be able to create an isochron by drawing circles in the transformed map!