Structural and functional robustness in public transportation networks of Latin American cities

This work assesses the robustness of the public transport systems in three Latin American metropolitan areas: Mexico City, Rio de Janeiro, and Buenos Aires. By integrating infrastructure and mobility data, we propose metrics to quantify both structural robustness and functional performance. We analyze the similarities and differences among these cities under complete bus-line removal scenarios that emulate realistic disruptions, such as service suspensions or operator closures. Open infrastructure data allow us to quantify structural robustness in terms of network topology and fragmentation. Complementarily, mobility data allow us to assess functional robustness by measuring trip feasibility and the additional travel costs that arise as lines are progressively removed. We recover known results for topological metrics, such as the fact that strategies based on line betweenness are the most efficient for fragmenting the network topologically. Across the three cities, we observe a strong correspondence between structural and functional robustness metrics. Furthermore, we highlight the role of line redundancy, with Rio de Janeiro exhibiting a more robust structural profile than the other cities.