Road-transport emission projections to 2020 in European urban environments

Road-transport emissions were projected to 2020 using the TREMOVE model to estimate the vehicle stock mix over EU15 and three new European member states (Czech Republic, Hungary, and Poland). The COPERT model was used to estimate the exhaust emissions of NOx, NO2 and PM2.5. Non-exhaust (tyre and break wear) PM2.5 and PM10 were also calculated. Emissions were projected following current legislation (CLE) measures and a scenario representing maximum feasible technical reductions (MFR). Projections to 2020 showed that CLE will bring 89, 25 and 50% reductions in NOx from gasoline passenger cars (GPCs), diesel passenger cars (DPCs) and heavy duty vehicles (HDVs), respectively, over 2000 levels, when comparing average emissions on a per vehicle-km basis. The corresponding reductions in the MFR scenario were 91, 53 and 67%, respectively. Despite these significant reductions, NO2 emissions do not seem to be effectively controlled for DPCs due to the increased NO2/NOx ratio of new and expected aftertreatment systems. Moreover, there is an almost 9-fold increase of NO2 emissions from mopeds, as they gradually shift to stoichiometric mixtures, four-stroke combustion and use of catalysts in the exhaust. Following CLE, PM exhaust and non-exhaust emissions will decrease on a per vehicle-km basis by 61% for DPCs and 63% for HDVs. Reductions by MFR over the reference year are estimated in the order of 77% and 65% for DPCs and HDVs, respectively. However, the increasing share of non-exhaust sources to the total PM emissions may hamper the effectiveness of exhaust control measures in meeting future urban air-quality standards.