Effects of traffic-related control strategies on urban air quality

An urban air quality management model called SEM has been applied to the urban areas of London and Berlin for the year 1993. Using detailed information on emissions (one and ten kilometre grid network), the road network, vehicle fleet composition, travel behaviour and meteorology, the model predicts annual average air quality at a central monitoring site and inside a nearby street canyon. Considered are all traffic and non-traffic emission sources of CO, NMVOC, C6H6 NOx and PM10 with a modelling domain of 100 km by 100 km around the city. A range of traffic-related control strategies, mostly hypothetical scenarios, were tested. These include changes in engine technology (e.g. replacing non-catalyst by catalyst cars) and trip reduction scenarios (e.g. a 10% decrease in the total number of commuter vehicle trips from outside Greater London into Central London). The predicted variations in long-term air quality have been analysed for the monitoring sites London Bloomsbury and Berlin Mitte, as well as inside the two street canyons Regent Street and Franzosische Stra ss e. The results of the modelling exercise are discussed and different forms of traffic-related control strategies compared to one another.