The MABA's overall CO specific emissions corresponded to the 1990 EU15 value, showing a 16-year lag in the incorporation of the European fleet technologies. A similar time lag of 10 years is observed with Australia and the United States. The large difference between MABA's specific emissions and those from Japan (11 times) is mainly driven by the different vehicle technologies present in the two countries. The same behavior was observed for NOx,N2O and CH
. These results highlight the importance of acquiring regionally measured EFs as the best proxy for local representativeness. The use of EFs from developed countries implied the underestimation of the emissions as follows: