The Federal Office for Spatial Development is currently reconsidering all the external effects caused by road and rail traffic. The available data were partly based on relatively old calculations which are now brought up to date. Thus safety (accidents), health costs and damage to buildings due to air pollution as well as noise are evaluated.
Currently, road and rail transport only partly covers its costs. The costs caused by transport emissions, noise, accidents and greenhouse gas emissions are, for the most part, met by the general public and not by those responsible. These costs are referred to as external costs. In the interests of fairness under the 'polluter pays' principle (Art. 74 para. 2 and Art. 85 para. 1 of the Swiss Federal Constitution), the aim is to identify these costs in order to charge the responsible parties, thereby internalising them.
Transport has a wide-ranging impact on nature and landscape. These complex effects were identified in a preliminary project and evaluated with regard to their relevance.
Three chains of influence are relevant, two of which it was possible to quantify and monetarise for the first time in the present work:
- Habitat loss
- Habitat fragmentation
- Habitat quality loss
These chains of influence were examined in seven different infrastructure types outside urban areas:
- Motorways, main roads, 1st class roads
- 2nd class roads
- 3rd class roads as well as single-track and multi-track railway lines.
The following relevant impacts of transport on nature and landscape were recorded: Habitat loss, habitat fragmentation and habitat quality loss.
- The impact on the appearance of landscape was not examined.
- Digital 3D aerial photographs were used to determine habitat loss between the 1950s/1960s and 1998/99 in a strip bordering the road and rail infrastructures.
- The monetarisation of habitat loss used a repair cost method.
- Habitat fragmentation was determined using current aerial photographs according to the requirements of different animal groups.
- The external costs of this fragmentation were calculated using the costs of constructing actual links between the habitat fragments.
- Habitat quality loss can be identified but not quantified and therefore not monetarised either.
The following relevant impacts of transport on nature and landscape were recorded: Habitat loss, habitat fragmentation and habitat quality loss. The impact on the appearance of landscape was not examined: The calculated external costs of transport on nature and landscape amount to an average of CHF 765 million/year (range: CHF 443-1,083 million/year; of which habitat loss comprises CHF 179-337 million/year and habitat fragmentation CHF 264-746 million/year).
Around 86% is caused by the road infrastructure, with 37% caused by motorways and main roads alone.
Around 14% is caused by the rail infrastructure. In the case of habitat loss, over 85% of the external costs are due to the road infrastructure.
The external costs of habitat fragmentation are distributed similarly to those for habitat loss: Around 87% are caused by the road infrastructure, of which just under 54% can be attributed to the motorways and main roads (wider roads require larger link constructions).
The resulting repair costs are comparable to those from the evaluation of the aerial photographs. Given the enormous variability of nature and the diverse calculation assumptions, the range of results is considerable. It could be narrowed only at great expense. As a rule, conservative assumptions were made in different stages of quantifying and monetarising the external influences of transport on nature and landscape.
Such assumptions are more likely to deliver low costs:
- The three chains of influence – habitat loss (area), habitat fragmentation (barrier effects) and habitat quality loss – capture the key external effects of transport on nature and the landscape. Effects which have a lesser impact, such as the way in which pollution and noise affect flora and fauna, cannot be covered by the study for methodological reasons. The costs calculated are therefore on the low side.
- Aesthetic effects and impact on the appearance of landscape were not recorded. - The reference period of 'the 1950s' is based on expert assessments and not on the expressed preferences of the population. However, prevailing attitudes about willingness to pay, and political decisions (e.g. revision of the Natur- und Heimatschutzgesetz [Federal Law on the Preservation of Nature and the Landscape]), indicate that this reference period is realistic.
- The delimitation between habitat loss caused by transport and that caused by farming is very difficult. It is possible that a proportion of the habitat loss thought to have been caused by transport could be attributed to agriculture.
- The monetarisation method selected favours the railways because the majority of the railway infrastructure had already been constructed in the 1950s. However, even where the rail infrastructure has existed since that time, the habitat loss estimated within the study area (+/- 10 m) was still assigned to rail transport, although it might have been caused by improvements or intensive farming.