This research establishes an approach to modelling a congested road network for air quality management, which enables the assessment of traffic management solutions that may create only subtle changes in the traffic flow regimes. Road network emissions have been calculated using standard factors taking into account details of vehicle fleet composition, average speeds and road type. Additionally, the use of microsimulation traffic modelling in conjunction with an instantaneous emissions model (IEM) has been adopted to allow comparison between methodologies and enable congestion sensitive analysis of the impact of air quality management measures on the network. Findings from microscale modelling have revealed that the use of an IEM to calculate emissions as an input for air quality dispersion modelling significantly improved the performance of the dispersion modelling when measured against monitored data. Moreover, this methodology has been successfully applied to assess the performance of a traffic scheme in Durham, UK.
Keywords: air quality, emissions, instantaneous emissions model, IEM, microsimulation, dispersion modelling