Evaluating and modifying a public transport network to achieve an equitable distribution of accessibility

Abstract

The provision of good accessibility is the main function of a well-functioning public transport (PT) system, the quality of which affects the ability of people to access basic needs such as employment, education, and healthcare. It is therefore important that PT accessibility is distributed in an equitable, or fair, manner. This thesis evaluates the equity of a PT network according to three distinct distribution principles, defined as alternative ideas of what constitutes a fair distribution of resources. Egalitarianism, proportionality, and sufficientarianism are applied in separate equity evaluations of the same area, resulting in the identification of zones of surplus and deficit accessibility according to each principle. When comparing the results of the three equity evaluations, it is found that both the locations and magnitudes of accessibility surpluses and deficits differ between principles. Some principles have deficit zones in common at the periphery of the study area, indicating that the borders of concessions may have been somewhat neglected in the service planning process. However, overall, the main finding is that a PT network that is equitable according to one principle may not be equitable according to another. It is also attempted to use the results of each equity evaluation to make frequency modifications to achieve a more equitable PT network according to each principle. Equity evaluation according to egalitarianism and proportionality were found to not be possible due to the circular calculations inherent in the methodology. It was possible to use the results of the sufficientarianism equity evaluation in network design, therefore this principle can be used as an input in the network planning process. Although further research is still required, these findings can help to inform the incorporation of equity in future PT planning policy, for example through inclusion in concession requirements.