In most public transit systems that run according to published timetable departing early is taken as more serious issue than departing late. It might seem count

In most public transit systems that run according to published timetable departing early is taken as more serious issue than departing late. It might seem counterintuitive, but inconvenience caused to passengers by arriving/departing late (small additional wait time) is significantly smaller than by departing early (missing the connection entirely and having to wait for the next one). IIRC in Prague's transit system drivers are fined for not observing the timetable without external cause and the fine for departing even one second early is same as for being several minutes late (and is relatively significant fraction of their monthly salary).