And by 'tube', I meant 'London Underground', of course. The best city in the world... suffering the worst transport problems in the developed world. (If you want to know how awful it is, just consider the train drivers who - while accepting a job that earns them significantly above average wage - decide to go on strike for more money.)
But back to LEGO! While there are many ways of presenting a map in LEGO the use of horizontally placed bricks for the background, and vertically placed perpendicular tiles for the awkward diagonals. It probably uses the train lights, but I'm not sure.
 technically speaking this is a tube diagram not map, because it's not geographically accurate, but only pedants like me would care!