The Swiss 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 (accident costs), health costs and damage to buildings due to air pollution as well as noise costs are evaluated.
Air pollution (e.g. particulate matter) due to traffic causes different types of building damages:
- Effective renovation costs due to increased renovation work on locations exposed to heavy traffic volumes.
- Costs due to deterioration of facade conditions on and off locations exposed to heavy traffic volumes, without direct renovation impact. The resulting reduced lifespan will lead to additional capital costs.
- Increased cleaning expenses on locations exposed to heavy traffic volumes.
The study relates to costs of building facades. It does not include possible damages to art and architectural monuments. The aim of this study is to quantify these (external) costs relating to building damages due to traffic in Switzerland in 2000.
Analysis of the empirical evidence: Analysis of an older study from 1992 by Wüest & Partner - literature evaluation - expert interviews - own in-depth data evaluations.
Extrapolation for Switzerland: The empirically realisable basics can be used to extrapolate total costs in Switzerland. The procedure includes several steps:
- The quantity structure is based on the building database of Wüest & Partner. This database includes all building facade surfaces, differentiated according to important types of material and can be called a solid empirical foundation. The buildings are differentiated according to different spatial types to better account for exposure loads.
- The cost rates for the different types of work will be updated through interviews with experts. Component-specific cost for construction work, renovation and cleaning work by surface unit are its central aspect.
- Renovation costs on locations exposed to heavy traffic volume can be calculated based on in-creased renovation work (reduced renovation cycles), on facade surfaces exposed to heavy traffic volumes and on the cost rates of the renovation work. Cost will completely be allocated to transport.
- Increased capital costs due to reduced life spans of facade surfaces under the influence of pollutant exposure will be calculated on the basis of land registry data, on facade surfaces not exposed to heavy traffic volumes and on cost rates for the construction of facade components. These costs will be allocated to transport and other sources.
- Cleaning costs on locations exposed to heavy traffic will be extrapolated based on exposed win-dows and glass/metal facade surfaces and specific cleaning work costs.
- Allocation of damages to the different sources and transport means take place, as a first step, based on exposure shares differentiated according to space respectively agglomeration type and as a second step according to their share of PM10 emissions.
Overall building damages due to air pollution amounts to 546 mill. CHF in the year 2000. Almost 50% of these total costs can be attributed to traffic (265 mill. CHF per year) whereas the rest (281 mill. CHF) can be attributed to other sources. From the 265 mill. CHF per year building damages that are related to transport, the biggest part of cost originates in the metropolitan areas and agglomerations. Overall, 125 mill. CHF per year originate in urban areas, 110 mill. CHF per year in the agglomerations and only 30 mill. CHF per year in rural areas.
Differentiated according to transport means, 93% of the costs can be attributed to road transport (i.e. 246 mill. CHF per year): 129 mill. CHF per year to road passenger transport and 117 mill. CHF per year to road freight transport.
Because of rail particle emissions (through track and wheel abrasion, brake abrasion, contact line abrasion and resuspension) rail transport also generates minor costs (14 mill. CHF per year).
Finally, 5 mill. CHF can be attributed to air transport. Average costs of different means of transport are as follows:
- Passenger transport: - passenger car: 0.13 Swiss cent per passenger kilometre (cent/pkm) - motorcycle: 0.09 cent/pkm - moped: 0.05 cent/pkm - coach: 0.2 cent/pkm - bus (public transport): 0.3 cent/pkm - rail passenger transport: 0.04 cent/pkm
- Freight transport: - delivery van: 1.6 Swiss cent per tonne kilometre (cent/tkm) - heavy goods vehicle (average): 0.7 cent/tkm - heavy goods vehicle: 70s: 1.3 cent/tkm - heavy goods vehicle: 80s: 0.9 cent/tkm - heavy goods vehicle: Euro 1: 0.7 cent/tkm - heavy goods vehicle: Euro 2: 0.6 cent/tkm - heavy goods vehicle: Euro 3: 0.5 cent/tkm - rail freight transport: 0.07 cent/tkm
The existing analyses support the estimation of building damages because of a new empirical evidence analysis and of new empirical basic data for the exposure load and facade surfaces of Switzerland. The results are therefore more than a reflection of a mere update, but a new evaluation of building damages caused by air pollution. Compared to foreign studies this analysis is significantly more sophisticated. The analysis also shows that costs due to air pollution can be proven. But at the same time it has to be mentioned that these cost are not very relevant in practice, but they are the calculated result of comparisons between different locations. This can also be allocated to the building industry because it is always improving materials and makes them more resistant to external impacts and loads. This may also indicate a decrease of the importance of damages in future. Particle emissions are today's most important cause, and they serve also as basis of the allocation to the different transport means. The biggest part on damages caused by exposure to heavy traffic is allocated to road transport. Here also the future prospective improvements (through cleaner diesel fuel and diesel engines) will lower the resulting costs. But it will be more difficult to reduce the likewise relevant particles which are caused by mechanical processes such as abrasion and resuspension. Rail transport also is a contributor to these processes.