ETC/ATNI Report 2021/6: Noise indicators under the Environmental Noise Directive 2021. Methodology for estimating missing data.

This report provides a comprehensive description of the methodology for gap-filling missing noise exposure data (i.e. data not yet reported by the Member States after the deadlines set by the Environmental Noise Directive). The report also explores a new method for major airports based on estimating the noise contour band when this information is not provided.

The experience of the three reporting cycles of the Environmental Noise Directive (END), which started in 2007, has demonstrated substantial delays in delivering noise exposure data. For that reason, methodologies to estimate missing data have been developed as early as 2013 to provide a complete overview of the extent of the population exposed to various noise sources.

This report reviews previous methodologies and provides a comprehensive description of the methodology to gap-fill missing data in all reported noise sources. In particular, it provides a systematic approach when regression is required (e.g. estimation of the population exposed to agglomerations roads based on the number of inhabitants). The gap-filling methodology is specific for each noise source, given the relevance of local conditions for noise exposure. For major roads and major rails, missing data is estimated by linear regression with the length of the transport network as the independent variable. For roads inside agglomerations, missing data is estimated by linear regression with the total population as the independent variable. For other sources inside agglomerations, the European average of the population exposed is applied. Finally, a new approach is described for major airports based on the estimation of the noise contour band considering the geometries of the runways.