Bus bunching occurs when delays cause buses to accumulate and arrive at stops closer together than scheduled. As the lead bus slows from crowding, the following bus catches up and passes it, resulting in buses arriving in bunches rather than spaced evenly. The document analyzes bus data to identify where and when bunching occurs on particular routes, finding it common in mornings and evenings at specific stations. Frequency maps show bunching is more severe in one direction between Triemlispital and Oerlikon stations than the other.

1. Modeling Bus Bunching
Andrea Farnham, Isaac Gravestock, Lukas, Mireia

2. What is bus bunching?
http://interactive.wbez.org/curiouscity/bus-bunching/
• Space between buses shrinks as the
front bus is delayed
• As the front bus gets more crowded,
it slows even more
• Emptier following bus gets faster
• Resulting accumulation of delays

3. • Where, when in the course of a day
and why does bus bunching occur?
• Can bus bunching be predicted?

4. line80[, diff:= ist_an_von-shift(ist_an_von), by=.(halt_kurz_von1, datum_von)]
• created a new variable that calculated the time difference between buses
arriving at each stop by day
• Defined bus bunching as <180 seconds

6. Occurrence of bus bunching by station in the morning

7. Occurrence of bus bunching by station in the evening

8. Frequency bus bunching mapped by station
(Triemlispital -> Oerlikon)

9. Frequency bus bunching mapped by station (Oerlikon ->
Triemlispital)