Low-Emission Strategies in a vehicular traffic context: A case study on San Salvario, Turin

Air pollution is a growing environmental problem, and emissions from vehicular traffic in large cities have a significant impact. Numerous strategies have been implemented in major cities to make urban areas more sustainable and livable. This study focuses on implementing two traffic emission mitigation strategies - a new 30 zone and the creation of new bike paths - in Turin, specifically within the San Salvario district. It evaluates their effectiveness using software to simulate a new mitigation scenario. The COPERT program was used for an initial analysis, using the typical vehicular fleet compositions of the area, while SUMO was used to further investigate the relationship between emissions and driving style, comparing only cars with different fuel and Euro standard. Both of the programs were used to compare a baseline scenario, where vehicles travel at a typical urban speed, with a scenario where speed is reduced to 30 km/h. COPERT's results highlights how speed reduction is not enough to actually reduce emissions; as a matter of fact, the analyzed pollutants show an higher value at a lower speed. This is influenced by the model used by COPERT, that doesn't allow to take into account the precise road configuration in this thesis' case study but employs a generic urban context, where emission factors associated to lower speeds are higher. In SUMO, instead, it’s possible to implement the road network of a specific area, as to analyze the behavior of a vehicle considering every urban element of the analyzed area. The results show that simply reducing speed is not enough to lower traffic emissions, as these are heavily influenced by typical urban factors like braking/acceleration, driving style, and road configuration. Implementing a new 30 Zone can be effective if it promotes a more fluid and less aggressive driving style which in some cases is only possible with an appropriate road configuration.