Modeling the effect on air quality of Euro 6 emission factor scenarios

To reduce traffic emissions effectively, from September 2017, newly registered cars will have to prove compliance with emission standards on public roads. RDE (real driving emissions) limits will be introduced in two steps. onformity factors (CF) are introduced to link RDE with laboratory limits. In this study, the effect of several emission factor scenarios on air quality was odelled. Conformity factors were varied between CF=1.6 and CF=3.3 in step 1 and between 1.2 and 1.8 in step 2. Road traffic emissions and NO2 concentrations were modelled for three urban main roads in Germany (“Am Neckartor” (Stuttgart, severe limit exceedance of annual mean NO2 in 2015), “Corneliusstraße” (Düsseldorf, average limit exceedance 2015), “Dachauer Straße” (Munich, compliance with the limit 2015)) for the years 2015, 2020, 2025, and 2030 for each scenario. The results were extrapolated to all German traffic-influenced air quality measurement stations. Depending on scenario, the fraction of traffic-influenced stations exceeding the air quality limit for annual mean NO2 is expected to be reduced from about 50 % in 2015 to 23 % up to 28 % in 2020, 7 % up to 10 % in 2025, and 1 % up to 4 % in 2030.