MODELLING EVALUATION OF EU ROAD TRAFFIC EMISSION STRATEGIES Giovanna Finzi, Veronica Gabusi, Marialuisa Volta 1 D.E.A., Universit` a degli Studi di Brescia, Via Branze 38, I-25123 Brescia, Italy Abstract: The comprehensive Gas Aerosol Modelling Evaluation System (GAMES) was used to investigate the impact of EU Directives on road traffic emissions scheduled for 2010 on photochemical pollution. The area under study is located in Northern Italy, where orographic features and the emissive mix represent a critical issue in ozone production and accumulation processes. The long-term period April- September 1996 was selected as the reference case, and an impact assessment simulation for the year 2010 was performed, including the future emission fields based on the current legislation. In order to evaluate the effectiveness of the EU road traffic abatement policy in Northern Italy, graphical indicators were computed and analysed. Copyright c 2005 IFAC Keywords: Air pollution, nonlinear systems, mathematical models, decision support systems, traffic control 1. INTRODUCTION Tropospheric ozone is considered one of the most significant pollutant with respect to its potential impact on human health and natural ecosystems, in terms of critical episodes and long-term ex- posures. To identify and to implement ozone re- duction strategies is a complex and difficult task; indeed, the formation and build up of ozone con- centrations are consequent to a large number of photochemical non-linear reactions taking place in the atmosphere and involving temperature, hu- midity, solar radiation as well on the primary emissions of nitrogen oxides (NOx) and volatile organic compounds (VOC). Thus, the effective- ness of ozone abatement measures is consequent to a great number of variables involved in its production and accumulation. In this framework 1 This research was mainly supported by MIUR (Italian Ministry of University and Research) and Universit` a degli Studi di Brescia (Progetto Giovani Ricercatori). air quality modelling systems can and must play an essential role in air quality management, as suggested in Directive 1996/62/CE (Palacios et al., 2002); in fact, they allow to study photochem- ical pollution and to analyse and assess appropri- ate emission reduction strategies. Throughout Europe, a wide range of modelling studies were performed to examine the benefits of NOx versus VOC control policies by means of sensitivity modelling simulations, mainly aimed at investigating the ozone response to precursors control, focusing on local critical ozone episodes (Blanchard and Stoeckenius, 2001), (Palacios et al., 2002) or on European scale (Simpson, 1995), (Zlatev et al., 1996). Road transport is widely recognized to be a significant and an increasing source of photochemical pollution precursors, be- ing one of the main sources of NOx emissions. In this framework, EU Directives in force up to 2010 ask for substantial NOx and VOC emission de- creases. This study focuses on the photochemical