![](https://www.nsl.ethz.ch/wp-content/uploads/2017/06/Understanding-metropolitan-patterns-of-daily-encounters.jpg)
Sun, Lijun; Axhausen, Kay W.; Lee, Der-Horng; Huang, Xiangfeng
2013
PNAS. Mehr
With the help of travel smart card data, we uncover daily face-to-face encounter mechanisms and structures by constructing a time-resolved in-vehicle social encounter network on public buses. We find individuals with repeated encounters are not grouped into small communities. A large, imperceptible, small-world contact network is formed across the whole metropolitan area.