Abstract: The rapid freight transportation increasing in urban and metropolitan areas contributes to congestion, air pollution, noise and to raise logistic costs, and hence the price of products. In addition, a combination of different types of vehicles on the road increases the risk of accidents. Moreover, the new policies of freight distribution provide daily deliveries. A so far distribution of goods has not been in accordance with people wishes regarding the city\'s space and environment. Sustainable city logistics solutions have to be implemented in order to riduce the effects of freight transport without penalising the life of the city. For example, as it happens in passenger mobility we can brave the problems related to externalities related to transport addressing to transit. It allows us to do not reduce accessibility and penalise the life of the city. At the same way, city logistics has to investigate the possible solutions that allow us to reduce externalities, to increase sustainability without damaging the city life. Around the world, different types of city logistics measures have been proposed and implemented, but sometimes they have not given the expected results. Thus, as it happens in the analysis of passenger mobility, in which we have different classes of measures that can be implemented in relation to city structure and level of demand, the same should be desired for freight mobility. In this context, the paper, within the field of city logistics sustainability, recalls the overview of measures to be implemented, in a "what if" framework, with strong references to the ex-post assessment carried out in order to support the definition of city logistics scenarios that should have to be evaluated ex-ante by simulation models. The analysis is done in relation to the goals of environemntal sustainability to be pursued and the main characteristics of analysed cities (e.g. population, density). In other words, the study presents the empirical relations among outcomes (e.g. reduction of greenhouse – CO2 - or air pollutant emissions – CO, NOx, SOx, PM) and city logistics measures. Both qualitative and quantitative trends of expected results related to environmental sustainability in function of city characteristics will be deepened. From this type of analysis, it will be possible to identify the maximum expected reduction of externalities obtainable from a given city logistics measure in relation to a specific city.