Review of Dutch rail diesel emissions calculation methodology

The Task Force on Transportation is responsible for calculating the emissions of environmental pollutants from mobile sources in the Netherlands. One such sources are the railways. As the last time the methodology for calculating rail emissions was updated to any major extent was in 1993, RIVM asked CE Delft to analyse it and make recommendations for future work. In the study CE Delft analyses the energy consumption of rail transport, especially from diesel consumption, assesses the emission factors used at present and makes recommendations for improvements.

Since the Dutch methodology was originally laid down, the fleet of railcars and utilisation of the rail network (including the new Betuwe line) have changed, without this being reflected in the emissions methodology. It was also found that only a limited number of studies have been published on diesel rail emissions, implying limited knowledge of diesel rail emission factors. At the same time, it is questionable whether the NOx emission factor currently used is representative for the Dutch railcar fleet, which is relatively young and therefore likely to have a lower NOx emission factor. We recommend performing practical measurements on diesel railcar emissions to update current emission factors and gathering more detailed data on fleet composition as well as age-dependent emission factors.

The energy consumption split across passenger and freight trains was also investigated. Based on the results, it is recommended to increase the share of passenger trains from 35% to 55-60%. A final issue is that certain regional lines are now being electrified, which will lead to new allocation factors.



Eelco den Boer, Maarten 't Hoen