[edoo]

Hah great analysis. One factor with bus' is the schedule is likely planned to minimize early arrivals at the risk of being late more often. Usually when a bus is early it has to sit and wait until its departure time. A late running bus can be more efficient, and if kept until departure time might not ever get a chance to average down the bursts of lateness.

[stormbrew]

I don't think this is always true. My city measures buses as being on time at inner stops as being between something like 5 minutes early and 1 minute late (yes, you read that right). Timing stops, where they have to wait, are pretty infrequent (mostly bus terminals).

I don't know how common it is but it does exist. And buses perpetually being early means that if you're on time you wait even longer for the next one.

[8note]

a very late bus grabs everyone from each stop, so the next bus ends up early because it skips a bunch of less popular stops