Overview
In December 2012, the Swedish government commissioned VTI to update the social marginal cost for using infrastructure for all modes of transport based on state-of-the-art knowledge in the research community. The task only involved state roads.
The Impact Pathway Approach has also been used to perform the calculations using Swedish data focusing on health. In these calculations there has been placed particular emphasis on how the influence of population density in the vicinity of roads influence the results from these calculations.
For noise we developed an exposure function based on the new EU-CNOSSOS model which accounted for the location of buildings close to a road while for air pollution we used results based on detailed calculations in the Stockholm area.
Results
The results, using updated input data from 2012 on kilometres driven, emissions factors from HBEFA etc., are in line with those presented in the EU handbook from 2014 “Update of the Handbook on External Costs of Transport” but lower than those currently used in analysis of transport investments in Sweden (the so called ASEK-values).
An important reason for this is that it has been used more detailed information on population exposure. There have also been concluded that there are geographical differences in the external cost for air pollution between the north and the south of Sweden. For both air and noise emissions there is also a difference between urban and rural areas. Based on the results we conclude that there are a number of issues where further research is needed, for example the possible interaction of air pollution and noise on human health.
There are also still questions regarding the dispersion of emissions and population exposure and how this varies between cities and within cities in Sweden, depending on for example meteorological conditions. For air pollution there is also the question of the formation of secondary pollutants and their dispersion pattern and if they contribute to an external environmental cost in addition to health. One particular source of emissions in Sweden is the used of studded tyres which contribute to very high concentration levels of particulate matter close to roads in springtime. Since the focus in this study was on state roads we have not addressed this pollutant in this report.