Traffic management definition and assessment strategies rely on results from successive stages of modelling: from traffic to air pollution concentrations. The objective of this study was to improve this modelling process. Combining microscopic traffic modelling and 3 pollutant emission modellings was performed: two using aggregated traffic estimates (HBEFA, Copert) and the other using vehicle trajectory (Phem). The studied area is part of the Lyon urban area (6,2 km², 2091 road sections). Traffic and emissions were simulated for 16 scenario resulting from modifications of supply or demand (traffic calibration on the afternoon rush hour). Copert and HBEFA estimations show many similarities and differences with Phem. Ranking of scenarios on the basis of their variation to the reference was performed and analysed. Copert and HBEFA provide the same ranking. To focus on the analysis of two scenarios, difference of NOx emissions per link were maped (only the higher variations). The relevance of dealing with both the network and the links spatial scales to assess the impact of the scenario was clearly shown