# No-boarding buses: Agents allowed to cooperate or defect

## TL;DR

This paper models a bus system with a no-boarding policy where passengers choose to cooperate or defect, analyzing the effects of individual behaviors on system stability and showing no herding occurs under certain conditions.

## Contribution

It introduces a novel model of heterogeneous passenger behavior in a bus system with no-boarding policies, incorporating inductive reasoning and bounded rationality.

## Key findings

- No phase transition or herding behavior when the control parameter is small.
- Feasible implementation of no-boarding policies without leading to bus bunching.
- Different subsets of agents playing at different rounds affect system dynamics.

## Abstract

We study a bus system with a no-boarding policy, where a "slow" bus may disallow passengers from boarding if it meets some criteria. When the no-boarding policy is activated, people waiting to board at the bus stop are given the choices of \emph{cooperating} or \emph{defecting}. The people's heterogeneous behaviours are modelled by inductive reasoning and bounded rationality, inspired by the El Farol problem and the minority game. In defecting the no-boarding policy, instead of the minority group being the winning group, we investigate several scenarios where defectors win if the number of defectors does not exceed the maximum number of allowed defectors but lose otherwise. Contrary to the classical minority game which has $N$ agents repeatedly playing amongst themselves, many real-world situations like boarding a bus involves only a subset of agents who "play each round", with \emph{different subsets playing at different rounds}. We find for such realistic situations, there is no phase transition with no herding behaviour when the usual control paramater $2^m/N$ is small. The absence of the herding behaviour assures feasible and sustainable implementation of the no-boarding policy with allowance for defections, without leading to bus bunching.