This report quantifies the marginal external cost of transport (congestion costs and environmental costs) using the Federal Planning Bureau’s PLANET model and compares this to the transport taxes levied. These indicators were not covered in the ‘Projections of transport demand in Belgium by 2040’, published in 2019 by the Federal Planning Bureau and the FPS Mobility and Transport. In that sense this report supplements this publication.
First the importance of the different geographical zones, road types and time periods for congestion is outlined, followed by the importance of the different pollutants and types of emission for the environmental impact. The results are based on the reference scenario described in the above publication.
Consequently, a monetary value is attributed to an hour lost, and by a ton of greenhouse gas emissions or local pollutants. In so doing, the marginal congestion and environmental costs can be calculated. These marginal congestion costs and their evolution differ widely depending on the geographical zones, road types and time periods. Overall, the congestion costs increase between 2015 and 2040. These differences in time and space are not observed for the environmental costs. The environmental costs and their evolution depend strongly on the monetary damage inflicted by greenhouse gases. When the monetary damage inflicted by greenhouse gases takes on a low value, the marginal environmental costs decrease by 2040. With a higher value the marginal environmental costs increase.
The marginal external congestion costs are considerably higher than the marginal external environmental costs. As a result of the prevalence of the congestion component, the marginal external costs of the different geographical zones, road types and time periods diverge. When comparing the marginal external transport costs for 2015 with the taxes levied, for each of the geographical zones, road types and time periods, it appears that these are rarely internalised in the zones susceptible to congestion. During rush hour passenger car taxes only internalise the external costs outside the zones susceptible to congestion. By 2040, the degree of internalisation is further reduced due to increasing congestion costs. For trucks, the degree of internalisation is even lower. The kilometre charge on toll roads, introduced since 2016, only internalises the external costs outside the zones susceptible to congestion during off peak hours.