HBEFA (The Handbook Emission Factors for Road Transport) is a model for estimation of fuel consumption and exhaust emissions. Distribution of the total annual vehicle mileage on weight classes and vehicle types, such as heavy lorries with and without trailers, has a large effect on estimated emissions in HBEFA. However, there is no reliable data to divide the foreign lorry annual vehicle on Swedish roads into different vehicle types and weight classes (segments). So far, it has been assumed that the foreign annual vehicle mileage is distributed in the same way as the Swedish vehicle mileage regarding different weight classes, and if the lorry is running with or without a trailer. One possible source to get more reliable data, is Eurostat’s transport data register, but these data are not available at vehicle level due to confidentiality.
VTI has conducted a field study aiming to get a better view of the heavy lorry combinations rolling on Swedish roads.
According to estimates from Transport Analysis, heavy lorries (Swedish and foreign) drove nearly 4.6 billion vehicle kilometres on Swedish roads in the year of 2014. The foreign-registered heavy lorries were estimated to account for approximately 15 per cent of this traffic volume, or about 0.7 billion vehicle kilometres.
Calculations in HBEFA based on the revised vehicle mileage data, and according to the estimate of the traffic from Transport Analysis, resulted in reduced emissions for all substances except for N2O which increased with 2 per cent. Examples of reductions is Pb -15.2 per cent, CO2 -1.9 per cent, CO -1.5 per cent, NOx -1.5 per cent, HC -4.6 per cent and PM -2.7 per cent.
It is necessary to revise also the distribution of Swedish lorries vehicle mileage on segments, because the present data is believed to have deficiencies. One possibility would be to gather statistics from the major Swedish transport companies, another possibility is to conduct a new field study.