MIRA External Costs

Internalization of external costs in Flanders

Do we pay enough for the negative effects of transport?
Upon request of MIRA, TML calculated the private costs, the marginal external costs and the degree of internalization for different road modes, rail, inland waterways and sea transport. The private costs are the costs for the user. The marginal external costs are the costs for society caused by congestion, direct emissions, accidents, noise, and damage to infrastructure; but for cycling also include the health benefits. These costs are marginal as we calculate the additional costs for society of an additional vehicle km. The degree of internalization shows to which extent the user pays via taxes for the external costs he/she causes.  

Is the level and the way of internalization good enough?
Current taxes and levies only cover part of the marginal external costs. The degree of internalization is the largest for road transport and more for passenger cars in particular. On average, a gasoline car even pays too much. For road transport, external costs and the degree of internalization vary strongly with the place and the time of the trip. From an economic point of view it would be better to differentiate the taxes.

What are the most important marginal external costs and which modes perform the best?
For road transport the most important marginal external costs are the costs of congestion, with the exception of motorcycles and LDV for which the accident cost is more important. For the other modes (rail, sea and inland waterways) the marginal external environmental costs is the most important cost element. For passenger transport the motorcycle has the highest marginal external costs. Within the group of passenger cars the highest marginal external costs are for the diesel car. They have the highest marginal environmental costs due to their higher emissions of particular matters. Collective transport such as bus and rail have lower marginal external costs per passenger kilometre than private modes due to their higher occupancy rate. For freight transport rail and inland waterways have lower external costs than road and sea transport.  

This report is an update and an extension of the report: ‘Internalization of external costs of road transport (2004)


The final report is available here and on the website of the Flemish Environmental Agency: https://www.milieurapport.be/publicaties/2011/betalen-we-voldoende-voor-de-negatieve-effecten-van-transport

TML contributed to the update of AG transport with a chapter on external costs. This report is available here and on the website of the Flemish Environmental Agency: https://www.milieurapport.be/sectoren/transport/achtergronddocument-transport.pdf/view



funded by

Vlaamse Milieumaatschappij (Flemish Environmental Agency)


Eef Delhaye, Griet De Ceuster, Sven Maerivoet


Eef Delhaye

+32 16 74.51.22
reference: 09.33