Reorganization of public transport systems in Global South cities and its relation with quality of life: A case study of Mexicali, Mexico

• Non-integrated Public Transport (PT) affects quality of life in Global South. • A detailed method is proposed to restructure PT towards trunk-feeder systems. • The method does not require significant resource investment. • The method reduces travel, walking, and waiting times for PT users. • Grater benefit is identified in PT users with lower quality of life. Despite global trends to promote sustainable urban mobility, Public Transport (PT) services in most small and medium-sized cities of the Global South still operate in a non-integrated scheme that promotes unsustainable mobility and negatively affects quality of life. Generally, these cities lack data for detailed analysis, so transport planning based on modeling and simulation is difficult to implement. This study presents a methodological proposal for restructuring PT systems in such contexts, with the aim of improving accessibility for the population with the lowest quality of life, while acknowledging data and resource limitations. The proposal is structured as a four-phase workflow, whose core contribution is a three-module method for route restructuring: i) definition of trunk routes, ii) optimization of sinuosity, overlay, and route lengths, and iii) definition of frequency and stop points. The method relies on information obtainable from official sources or generated with minimal effort, making it applicable to other urban areas. The method was applied to the case of Mexicali, Mexico, and the resulting network was evaluated through modeling to assess its impacts on both all users and those with a lower quality of life. Results show that the restructured network reduces travel, walking, and waiting times, with greater benefits for users with a lower quality of life. Overall, the findings indicate that in Global South cities with non-integrated PT systems, the proposed method is feasible and can enhance system efficiency, benefiting all users, particularly those with a lower quality of life.