The European emission model HBEFA (Handbook of Emission Factors – www.hbefa.net) is the main model used to calculate air emissions, fuel consumption and energy use connected to Swedish road traffic on the national, regional, and local level. HBEFA was developed in the mid 1990:s and is managed jointly by Germany, Austria, Switzerland, Sweden, France and Norway, with some support from the EU Joint Research Centre through their coordination of the European collaboration ERMES (www.ermes-group.eu). In Sweden, HBEFA is managed by the Swedish Transport Administration.
The data needed for reliable calculations of the emissions and fuel consumption of the Swedish road vehicle fleet is in part provided by the general EU data compiled in the model (e.g. emission and fuel consumption factors for different vehicle types and traffic situations) and in part based on annual statistics, e.g., on vehicle stock and vehicle mileage travelled (VKT) provided by various Swedish authorities. However, some important calculation parameters are not updated on a yearly basis. This means that the adaptation of HBEFA to Swedish conditions would gradually deteriorate, resulting in declining quality over time in the Swedish emissions and fuel consumption statistics, as well as in corresponding forecasts and scenarios.