Or we can monitor the velocity with which people are moving with their phones on a highway, and the phone company can see, as the velocity is slowing down, that there's a traffic jam.
Kita bisa memantau kecepatan orang-orang di jalan raya dengan telepon mereka, perusahaan telepon bisa melihat, kalau kecepatannya berkurang, berarti ada kemacetan.