External Costs of Passenger Transport in Belgian Cities

The objective of this paper is to present intermediate results of ongoing research projects concerning the assessment of marginal, external costs of transport in Belgium. These studies cover all environmental impacts from different modes (road, railway and waterway) for both passenger and goods transport. Within each transport mode, distinction is made between different options (e.g. motor/fuel technologies, traffic density, location). The presentation will focus on the environmental impacts of airborne pollution from urban passenger transport. The assessment of these environmental impacts is based on the ExternE methodology and it is part of a European wide project co-funded by the European Commission. It is based on a detailed 'impact-pathway analysis,' which quantifies impacts on human health and the environment in 4 consecutive steps: specification of emissions, dispersion simulation, impact assessment with dose-response functions and monetary valuation. This methodology is applied to Belgian cities to demonstrate the importance of urban population density. The results show the importance of public health impacts as well as those of greenhouse gas emissions. The paper will focus on the differences between different technologies, fuels, traffic conditions and locations. Based on this data we will discuss to which extent the benefits from stricter emissions standards are compensated by changes in the Belgian car fleet. It shows that the benefits of the introduction of catalysts for petrol cars are smaller than one might have expected. Public transport and private cars will be compared, taking into account seat occupancy rates. Present-day diesel busses perform quite well provided their seat occupancy rate is high enough. Older diesel busses however are likely to have higher impacts compared to modern petrol cars