A proper planning of mobility can reduce air pollution due to road traffic. A crucial role, also aiming to improve sustainability, is played by the local Public Policies. Public Policies and initiatives can facilitate air pollution control, but an environmental consciousness has to be spread too. According to this principle, Ancona Provincial Authority is aiming at minimising the environmental impact of road traffic by persuading commuters to switch to public transportation systems.The aim of our work is the evaluation of improvements of air quality in a set of scenarios that could take place according to the Provincial Authority Policies. The study has been developed for the whole Ancona Province considering the exurban mobility network. The Province Offices provided data about the present passenger mobility scenario and the possible scenario based on an implemented public transportation system better responding to the local demand. Tangible reduction of the emissions from transportation is generally expected.The results are summarized by two main indices: the load of pollutants for each arc supports the decision-making process on the validity of the planned scenario, while the load of pollutants per person for each arc offers a social responsibility index to help the Public Administration to implement a sustainable and responsible culture in the citizens.