Uncertainty Estimates and Guidance for Road Transport Emission Calculations

Abstract

This is the final report of a study on the characterization of the sensitivity and quantification of the uncertainty of road transport calculations performed with COPERT 4. Two case studies were examined: one referring to Italy which is considered as a country with very good knowledge of the operating vehicle stock and the total activity in its territory. The second situation refers to Poland, where some of the older vehicle technologies do not follow the European classification and this increases the uncertainty in the calculations. Other differences between the countries include the difference in ambient conditions and the much younger stock of the fleet in Italy compared to Poland. The report provides the uncertainty ranges of the COPERT 4 emission factors and modelling parameters. It also characterizes the uncertainty of the input data for Italy and Poland. The most influential variables were also identified, using a screening technique (Morris) and Monte Carlo simulations. Finally, the uncertainty of the calculations was quantified by performing over 6000 simulation runs per country. The results of the simulations have been also used to provide guidance for road transport inventory calculations, following the methods proposed in the EMEP/EEA Atmospheric Emission Inventory Guidebook.