As road traffic is a major source for urban air pollution there is a need to link traffic models with the modelling of air pollution in order to analyse the impacts of transport policies on the environment and human health. The cause-and-effect chain from the traffic activity towards the concentration of air pollutants and population exposure is complex. Against this background, an approach is developed that links the multi-agent-based transport model (MATSim) with the calculation of air pollution using the Operational Street Pollution Model (OSPM). Traffic-related air pollution is modelled as detailed as possible while still being applicable to large-scale scenarios. Simulated hourly mean nitrogen oxide (NO_x) concentrations are compared with concentration measurements showing a similar pollution level and diurnal pattern at a site along a street canyon in Munich, Germany. Nitrogen dioxide (NO₂) emissions and concentrations are simulated for an area bounded by the major ring road of Munich, Germany. Locations with a high concentration level can be identified and the effects of a changing traffic demand through the introduction of a speed limit are shown.