Urban sustainable mobility. Part 1: Rationality in transport planning

The impact of the transport sector is in the range of 20%-40% in terms of consumption of fossil fuels and emissions of greenhouse gases and particulate matter. In this context, policies aimed at reducing these effects are very important. Many urban areas are trying to adopt planning strategies aimed to a sustainable use of resources often referred to as sustainable mobility. These policies are very different in terms of costs and expected benefits, and the effects of these policies and their combinations are difficult to anticipate on a purely intuitive basis and sometimes the end effect could be contrary to intuitive expectations (e.g. policies aimed to reduce pollution, ending up in increasing it). In this context, the concept of eco-rational planning assumes a central role. This means identifying the right mixture of interventions to be implemented on the transport system that is: rational for the transport system (e.g. reduction in terms of congestion, traffic accidents, travel time) and sustainable for people's health and for the environmental (e.g. emissions reduction) and requires minimal economic resources (e.g. lower monetary cost per unit of CO2 saved). The paper discusses the importance of rational decisions in transport planning.