COMPARATIVE-ASSESSMENT OF 2 FORECASTING MODELS FOR ROAD TRAFFIC EMISSIONS - A FRENCH CASE-STUDY

Two models for the forecasting of road traffic emissions, developed in dependently and in parallel, are compared: POLLEN, developed for a nat ional application (France) and FOREMOVE, developed for application on a European Community scale. The analysis of the methodological charact er of the two algorithms shows that the models are fundamentally simil ar with regard to the basic calculation schemes used for emissions (ve hicle and fuel split, hot and cold-start emissions, evaporation losses ). The divergences are mainly classified into two groups: (a) differen ces in the basic statistical data of the past coupled with differences in the underlying assumptions in the development of the future scenar ios and (b) differences in the emission factors used. These result in future emissions, which, although presenting similar general tendencie s, are substantially different as regards the calculated emission leve ls.