This competition means that buses do not cluster as they do in the UK, and act as a quantum chaotic system. Quantum chaos is the chaotic way sub-atomic particles are distributed in space and time. No company is responsible for their wages, and there is no timetable either. To maximise their income, the drivers need to pick up as many people as possible, leading to stiff competition for fares. To prevent clusters of buses, drivers go so far as to employ people at checkpoints along their route to tell them when the last bus left the area.
Drivers can then speed up or slow down to increase the chance of picking up more passengers.
Although this system is far from being of quantum origin, the fluctuations in the time intervals between subsequent buses arriving to a given bus stop display exactly the same features as observed in the chaotic quantum transport', said Seba. For the first time, the universal nature of quantum chaos theory is demonstrated. The surprising similarity of bus distribution to quantum chaos theory is explained by coherence - having the same energy. In the quantum case the coherent propagation of the quantum particles through the system leads to complicated interference phenomena and finally to the observed universal properties. In the case of buses in this Mexican city the coherence is a certain synchronisation between buses operating on the same line.