Ever since Harry Beck designed his iconic schematic map of the London Underground in 1933, other transit agencies have followed suit with their own abstract maps. Transit routes are shown as color-coded straight lines with sharp turns. Stops are equidistant, and the physical geography is omitted.
Navigating Tokyo’s rail transit was easy for me as a teen growing up in a western suburb of Tokyo. I just needed to know walking directions from a station near my destination. I could look at the JNR Tokyo map and quickly determine which trains to take and where to transfer.
Transit agencies create abstract maps to highlight the network structure of the system. Who cares if you’re crossing a river if all you need to know is the connecting line between two stations?
Schematic bicycle maps