The assessment of policies for sustainable urban mobility features two basic characteristics: incommensurability and strong uncertainty. This is why multiple dimensions of evaluation and a structured room for collective deliberation and learning should be considered.
A participative procedure is used to select a core set of performance indicators of policies for sustainable urban mobility. Citizen participation and stakeholder involvement are obtained through a national sample survey and a deliberative multi-criteria analysis, respectively. This procedure is applied to the Italian case.
Citizens are more oriented towards reducing private transport costs, air pollution and traffic accidents; stakeholders are more in favour of improving car-free accessibility and reducing the consumption of land and public space generated by urban mobility. The resulting core sets of indicators are highly sensitive to the threshold chosen for the selection. Using a lower cut-off threshold, four performance indicators are shared between the two sets: ‘CO2 from transport’, ‘Quantity and quality of public transport’, ‘PMx, COVNM, NOx, CO from transport’, ‘Death and injuries from traffic accident’; using a higher cut-off threshold the two sets feature no intersection.
Further testing at a local scale is needed in order to explicitly consider context-specific objectives, indicators and data; stronger interactions among experts, citizens and stakeholders are needed in order to avoid the generation of equivocal results.