An Integrated approach to modelling traffic pollution in the urban environment.

To meet global air pollution targets, public authorities are increasingly seeking reliable practical tools for assessing traffic pollution impacts. This paper outlines a method which combines traffic models with other models to assess the total effect on urban streets. It aims mainly to produce a model that can predict the distribution in space and time of road traffic pollution in realistic 'street canyons', where the street passes between parallel rows of tall buildings. The model can be made site-specific by including the topography of the particular canyon being considered. The Paramics traffic microsimulation model was used as an emissions model. Mathematical models were also used for: (1) canyon wind field and wind flow; (2) the mean velocity field; (2) the turbulence field; and (4) pollutant dispersion. The paper presents in some detail the application of this integrated modular approach to a simple illustrative example, the study of the fate of one emission of carbon monoxide from one vehicle. A street in Edinburgh was simulated. The paper shows how the individual models can be combined to produce a complete practical model for predicting the distribution of road traffic pollution in urban streets. Any of the models may be replaced by an alternative model