For anyone who finds this interesting, I recommend reading Underground Maps Unravelled, by Robert J Maxwell: http://www.tubemapcentral.com/writing/umu.html http

For anyone who finds this interesting, I recommend reading Underground Maps Unravelled, by Robert J Maxwell: http://www.tubemapcentral.com/writing/umu.html http://www.tubemapcentral.com/writing/umu.html It covers the history of London Underground maps and signage, analysis on how/why certain map elements help users, and contains a number of painstakingly recreated historical and theoretical transit maps to illustrate the points.