Geographically specific transport emission inventories

On behalf of the European Environment Agency (EEA) CE has carried out a review of the possibilities to create geographically specific inventories of road and rail transport emission. Such inventories at various sub-national geographic (regional) levels on the one hand require regionally specific data on transport volumes, the distribution of traffic flows across time and space, characteristics of the vehicle fleet, and on the other hand require emission factors that take account of geographically specific circumstances related e.g. to levels of congestion, climate and geography (e.g. mountains). A quick scan of available transport statistics shows that regional transport data are to various extents available in a number of EEA member states, but such data have varying formats and are often not shared in European databases. Available emission factor models for road transport allow geographic variation of a large number of variables relating to e.g. fleet composition, road types and traffic situation as well as to geographic and climatic conditions. Available emission factors for trains, however, are found to be less versatile and sophisticated than the emission factor models available for road transport. It is concluded that the possibilities for setting up geographically specific transport emission inventories by the EEA on the basis of existing data for road and rail are currently limited by the availability at the international level of appropriate transport statistics rather than by the limitations of available emission factor models. A more in-depth review of the availability of regional transport data at a national level in all 32 EEA member states is recommended.