This paper focuses on the results of a study that modelled European cities’ pathways to zero-emission urban mobility by 2030 through the development of potential transition scenarios. Each scenario is built on set of sustainable policy measures, whose impacts is quantified through a series of indicators as output results. The assessment is realized through MOMOS, a quantitative tool which allows to simulate and quantify in a simplified way the impacts of potential mobility transition scenarios in cities. Four potential scenarios, each one with a different focus and a specific combination of policy measures, have been simulated and applied to five European cities. The main output of the paper consists in the calculation of the CO2 emissions reduction associated to each scenario, and of a series of transport, environment, social, and economic indicators.