Graph connectivity
If you’ve ever used a city’s public transit network to get around, you may have wondered about how the city chose to put the train or bus stops where they did. There are many factors at play, but if you look at an ideal case, then you can boil the choice down to two related factors: connectivity and latency.
Think about the experience of a train rider, let’s call her Alice, visiting her friend, Bob, across the city. It would be great if there was a stop right next to Bob’s house because, then, Alice could see him right after stepping off the train. Of course, you can’t put a train station in front of every house, and after a certain point, adding more stops would increase the average trip time.
Every time you change the number of stops or connections, you may affect how long it takes to get between any two destinations in the system. Typically, the job of planning where to place public transit stops is done with thought and...
