By David Lee and Dietmar Offenhuber
Just like human beings, some bike stations seem to find others more attractive. We identified cases where bikes from one station were "biased" to travel to other stations. We divided actual trips between stations with expected trips (based on overall trip share of start and end points, similar to a Pearson's chi-squared test); the higher this ratio, the more those stations were biased to each other. For instance, the stations at JFK/UMass and at UMass Boston only have eyes for each other, while Brookline Town Hall and South Bay Plaza have an unexpected affinity. Cambridge stations favor Cambridge destinations; Boston stations aren't so picky. And, just like humans, most stations are self-obsessed, with disproportionate numbers of trips ending back where they started.