Indicators for sustainable mobility in the cities

The creation of a sustainable transport system is the main objective of European transport policy. This system should encourage facilities to connect all people and should be linked with economic, social and environmental aspects of society. Current trends and future challenges will meet a growing "accessibility" demand, highlighting concerns about the sustainability of transport. Therefore one of the priorities of transport policy is the improving of overall quality of transport, including aspects related to: personal safety, accidents and health hazards reduction, protection of passengers rights and of accessibility to remote areas. This paper is dedicated to sustainable development, with particular attention to urban transport and to daily mobility of citizens. It is important to analyze all the aspects that make it possible to clarify a definition of "sustainable transport". Their analysis has to be related to the individuation of a set of indicators that simultaneously take into account the three dimensions of sustainability: environment, economy and social issues. This, set should help to take decisions on policy and planning of urban transport systems. A limited and easily available set of indicators is more convenient to be used, but it may overlook important impacts, thus distorting planning decisions. A broad set of indicators can propose more quality in terms of completeness, but it has characterized by incredible data collection costs and by serious difficulties of interpretation. This study is based on the results of a survey carried out to verify feasibility and usefulness of such indicators for sustainable urban mobility in a particular territory. Values assumed by economic, environmental and social indicators are referred to the city of Palermo. A survey on family shifts was carried out in this city. It aims to the creation of a set of indicators that would allow comparison between different urban transport strategies. Finally, we analyze the possibility to generalize the proposed set of indicators and the role that they could play in sustainable transport policies development and implementation, even in different urban contexts.