Revision of the vehicle noise emission test method: a serious need for serious changes

In the EU Green Paper on Future Noise Policy of 1996 it was already concluded that the total effect of EU and Member States legislation on environmental road traffic noise was unsatisfactory until then. This was underpinned by extensive studies in the late nineties in the Netherlands, Germany and other countries. A very recent study in the Netherlands shows that in the last 30 years passenger cars in real traffic have not actually become quieter, but slightly noisier. Only the noise emission of mainly heavy trucks has decreased at urban speeds. The increase of passenger car noise emission is not in line with the EU objective to reduce road traffic noise, especially in urban areas. An important reason for this is that the current noise emission type approval test, as described in ISO 362, no longer reflects the real driving behaviour in urban traffic. Therefore the UN-ECE GRB published a new test method in 2007, which is based on a revised ISO 362 standard of the same year. During a period of three years the new method was used for monitoring purposes in parallel with the existing test method, and a database of parallel test results was collected by the EU. This database was used to investigate the qualities of the new method and to quantify the differences between the results of the two methods. Next, several EU policy options for revised noise emission limit values were investigated with an accompanying assessment study on the environmental, social and economical impact of each of the options.