A similar one here: http://www.cityam.com/234508/this-alternative-tube-map-shows-you-the-travel-time-from-every-station-on-the-london-underground http://www.cit

A similar one here: http://www.cityam.com/234508/this-alternative-tube-map-shows-you-the-travel-time-from-every-station-on-the-london-underground http://www.cityam.com/234508/this-alternative-tube-map-shows... https://petertrotman.com/special/london-underground-travel-time-map/map.html https://petertrotman.com/special/london-underground-travel-t... . I don't know who can claim priority or if they worked independently.