Summary and conclusions, Miljøstyrelsen

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Summary and conclusions

The Danish Government is working on a strategy to reduce the noise from roads. A lot of different initiatives are being evaluated, taking the cost and benefits into consideration.

In general it is easier to estimate the direct cost associated with an initiative than the value of the environmental effects which are more indirect. Road noise effects people's health and welfare. To be able to estimate the benefits associated with reducing the noise from roads, it is necessary not only to quantify these effect, but also to put a price on them.

Part of the welfare effects from road noise can be evaluated by using the hedonic pricing method. This method makes use of the fact that the price of a house reflects several parameters such as housing area, age and numbers of toilets and even the position of the house. By estimating a model including these elements, it is possible to isolate the effect of one single parameter, in this case: road noise.

It is important to point out that the results from this study only concerns existing roads and not the effect of road noise from the construction of new roads.

The study shows a significantly lower price of houses affected by road noise compared to other houses. The prices of houses affected by road noise above 55 decibel (dB) situated near "ordinary" roads decline by 1,2% pr. dB. The prices of houses placed by motorways decline by 1,6% pr. dB.

The reason for the greater effect near motorways can be due to the fact that noise from motorways is more constant, and thereby more annoying, than noise from "ordinary" roads. Another reason could be that a motorway is a bigger barrier in the landscape and is more annoying to look at. In that case it isn’t the noise that causes the increased effect on the prices of the houses near motorways. It is not possible from this study to conclude which of these possibilities is the most feasable.

If houses exposed to road noise below 55 dB arealso included in the model, the average effects on the house prices are smaller: 0,9% for houses placed by "ordinary" roads and 1,5% for houses placed by motorways.

The model is based on data from 8 areas in Greater Copenhagen. If these areas are analysed separately, the effects on the house prices vary from 0,75% to 1,01% for houses situated near "ordinary" roads and 1,06% to 2,29% for houses situated near motorways. In this model, houses exposed to road noise below 55 dB are also included.

The effects on house prices in these separate areas are quite similar to houses situated near ordinary roads. That is positive in relation to transference of the results to other areas, also called benefit transfer. The larger variation in the results from houses placed by motorways indicates that it is more difficult to use these results in benefit transfer.

It is not certain that it is the exact level of noise a potential house owner considers when he is buying a house, but rather the distance from the noisy road. In one of the models this parameter is included together with a parameter that describes if a certain house is placed in the first row to the noisy road or not.

A house placed in the first row to the noisy road is worth 6% less than a house not placed in the first row. This is equal to 120.000 dkr for a house worth 2 mio. dkr.

In addition there is an effect of increased distance from the noisy road. The house price is increased with 0,05% if the distance increases by1%. If a house worth 2 mio. kr.is situated 100 meters from the noisy road, then the price of the house would increase by 900 kr. if it was placed one metre further away from the road. If the house was placed 20 meters from the road the house price would increase with 4.600 dkr. if it was placed one metre further away from the road. The closer the house is situated to the road, the greater is the effect of being placed further away. Corresponding to this the more expensive the house the greater the effect.