Emissions of the regulated pollutants were measured on a chassis test-bed from Euro 1 and Euro 2 heavy duty vehicles, following typical and specific driving cycles. Relatively strong correlations were found between the four pollutants and the CO2 emissions or the fuel consumption plus the mean speed in some cases. Therefore the authors propose technology related relations which apply to diesel vehicles between 3.5 and 44 tonne GVW running on flat roads. Functions are different for uphill roads at steady speeds. The emission factors are thus simply derived from the fuel consumption and the vehicle mean speed, both variables being easily obtained from the driver or precisely from a speed profile (obtained by modelling or monitoring) for any trip. Taking the fuel consumption as the main independent variable, they integrate many variables such as engine torque, vehicle speed profile and driving behaviour. This global approach has the advantage of simplicity and swiftness. These simplified functions could be used in rapid inventories for specific projects. (A)
Samenvatting