“Albert-László Barabási and colleagues monitored 100,000 users for 6 months and recorded the location of the cell phone tower that transmitted each call or text message. The team found that:

- most people stayed close to home, and a select few regularly took long trips. … regardless of how mobile they were, people returned over and over to a few top locations with similar probability. For example, two users would have roughly the same chance of being found in their third-favorite spots, whether it was the gym or the theater. These hangouts were often located near the path between their top two destinations–usually home and work
- most people traveled very short distances most of the time, while some traveled great distances.
- each individual’s data fit into the same mathematical model—a type of power law—that predicts the probability of finding a person in a certain location. That probability distribution is dependent on an individual’s average travel distance and decreases the further he or she roams. Human mobility and how we travel is so amazingly complex,” says Max Planck’s Brockmann. “What is very strange is that despite this complexity, all the traveling behavior can be accounted for by very simple mathematical laws.”

Potential applications: traffic forecasting and urban planning.