These attenuation factors
reflect the expected reduction in emissions for each vehicle category compared to the emissions produced for the reference year
(2000). In this respect, a value greater than 100% (e.g. diesel PCs in
Fig. 5) means that future emissions for this particular vehicle
category are expected to increase according to the CLE scenario and
that more stringent measures are required in order to reduce future
emissions, as demonstrated by the corresponding results of the
MFR scenario. Similarly, NOx emissions for LDVs (Fig. 5) are
expected to decrease only slightly up to the year 2015 due to the
introduction of more technologically advanced vehicles in the fleet.
However, according to the TRENDS model the number of these
vehicles is expected to increase considerably in future years. For
that reason, it is estimated that the overall NOx emissions produced