  Bus bunching is a curse of transportation systems such as buses in a loop.
Here we present an analytical method to find the number of revolutions before
two buses bunch in an idealised system, as a function of the initial distance
and the crowdedness of the bus stops. We can also characterise the average
waiting time for passengers as the buses bunch. The results give a better
understanding of the phenomenon of bus bunching and design recommendations for
bus loops.
