I grew up in London, in the 1950s when, with little else to do, kids my age travelled about the city, visiting places, seeing the sights. Nearly all these trips included a ride on the London Underground, the Tube. It was cheap, it was reasonably safe, and you could rarely get lost because they had the very best maps.
The famous Tube map designed by Harry Beck in 1933 was our guidebook and our treasure map.
The present day Tube system is far more complex, but the structural integrity of the map is always retained — because it works!
I am sure this early exposure to the Map fed my life-long interest in data visualization. I was interested, therefore, when I saw a story about a team of theoretical physicists and mathematicians who have published their data for selecting the most complex subway map of all.
For its study, the group analyzed maps of the world’s 15 largest metro transit networks, as determined by total stations. They considered all the trips a traveler could make from Point A to Point B with two connections, then determined the fastest possible path for a given trip. That framework aligned with behavioral research showing that people can store up to four pieces of information in their working memory at one time—in this case, a trip’s origin, its destination, and two transfer stations. The result was a “cumulative” complexity rating.
And the winner as the most complex subway map is the New York system, closely followed by Paris and Tokyo. London came fourth.
I rather admire the Moscow metro map because it lays out an honest vision that centralized control is important to an autocratic state, and it is important that the outlying “limbs” of the system can communicate one with the other only by going via the centre.
Of them all, I believe the Seoul subway system map is the most difficult for me to read: