Traffic noise in Europe: A comparison of calculation methods, noise indices and noise standards for road and railroad traffic in Europe

As the international dimension of environmental laws and legislation is gaining in importance, it has become increasingly essential to compare and assess international data. Can international data on noise, often produced by using different national calculation methods, be compared? And what does it mean for (inter)national noise policy? This paper focuses on international data on noise created by road and railroad traffic. Research shows possible differences in the outcome of noise calculations using different national methodologies of up to 15 dB(A). Furthermore, national noise indices and noise standards differ considerably, making it even more difficult to compare data on noise exposure. Therefore, harmonization of calculation methods and noise indices, as initiated by the European Commission, is a necessary first step. Although noise standards are left to the Member States, an effective European noise policy would be enhanced if the same type of indices were used for both noise-level calculations and noise standards. L_aeq type indices are recommended in this regard. Although harmonizing noise calculations and using the same kind of indices would make noise data more comparable, it would still not make Europe quieter. This is why noise measures, preferably at the source, are necessary. The European Commission in Brussels plays a major role in introducing these noise measures. Reduction of tyre noise by tightening emission limits is the most promising option. This may be supported at the national level by applying silent pavements. Integrating noise into spatial planning is the most cost-effective option at the local level.