A Graph-Based Study of the Impact of Carpooling on CO2 Emissions

Every day we hear about the current state of the climate and how it is degrading very quickly. It is urgent to study ways in which people can change and improve their daily lives towards more sustainable habits. This paper studies graph-based simulation scenarios, focusing on both human and infrastructure characteristics, which could lead to a potential reduction in CO
₂
emissions. We compare alternative policies with an upper-bound base scenario, in which people use their own cars for their sole use. Most of these scenarios are based on Dijkstra's shortest path algorithm, while others serve to underlie our reflections on the feasibility of using minimal spanning trees to solve the problem. The zone selected to illustrate this study is the coastal area of Espinho, a city in Portugal. It is shown that the scenarios with carpooling starting on the cut vertices of a tree generated by linking Dijkstra's shortest paths of each agent yield the best results. This approach leads to a reduction in carbon emissions of between 25% and 30%.