The irreducibles: The causes of non-propensity to shift to public mode to access university campus

University commuting has a strong impact on traffic congestion and pollution in urban areas. In Italy, this phenomenon is even more prominent since most universities are located in urban areas without adequate housing services in the surroundings. Therefore, it could be important for universities to implement policies that help commuters switch from private vehicles to public modes. This paper focuses on Milan Politecnico (today about 54 thousand people between students and staff) and outlines the characteristics of the car users’ profiles that are less willing to switch from car to a sustainable mode. The study involves a sample of 2 646 car users of the two main campuses, out of a much larger population using other modes. The paper builds a Multinomial logit, in which three different commuter specifications are defined: “car lovers”, people using car without taking into account other options, “car captives”, people obliged to use car, and “switchers”, car commuters willing to switch. The first two specifications are defined as “irreducibles”: people who declare they do not want or cannot switch. The model uses individual spatial location, socioeconomics and social behaviour factors as independent variables. Since location could play a role in changing propensity, the paper also includes a spatial analysis to check for possible missing spatial variables. We identify the main causes of rigidity in commuting switch behaviour and, according to the results, we provide policymakers and universities with consistent strategies to promote public transport use. The policies must be differentiated to address the two groups of irreducibles: car lovers typically do not respond to improvements or subsidies to public transport and must therefore be addressed with pricing and parking limitations. Car captives, instead, are such due to their location: not so far but sprawled. From the university point of view, provision of residences near the campuses or targeted subsidies and multimodal solutions for frequent travellers and those living in cities may increase the sustainability of commuting.