Evaluation of numerical models used to simulate atmospheric pollution near roadways

Abstract : Numerical modelling of traffic-related pollution can be useful to check compliance with regulatory thresholds, compare the atmospheric impact of various traffic scenarios or represent roadside concentrations in air quality maps. Because of operational constraints, local actors usually make use of parametrised models which are easy to implement but require caution and rigour in their application. Since 2007 an Internet information base including data sets, technical information and reference methodologies, has been built up by the French Central Laboratory for Air Quality Monitoring (LCSQA) to help local actors in evaluating their modelling tools. In addition, simulations have been performed for different types of streets to provide examples of model evaluation studies and draw some indications about the application framework of a few commonly used models. The results of those tests are presented and discussed for two street canyons and one semi-open street located in the French city of Nantes