Development Possibilities of Environmental Noise Propagation Modelling

Abstract

Noise pollution poses a critical issue in today’s world. In Europe, road traffic noise is considered a major environmental pollutant in urban areas, being a continuous nuisance source impacting several aspects of life. Road traffic noise is ranked as the second most significant environmental noise source affecting the mental health and daily activities of individuals in noisy environments, thereby influencing their wellbeing. Following fine particle pollution, road traffic noise is the most common environmental risk factor to human health in Europe. Its mental and physical adverse health effects are mainly caused by the loud engine sounds, the continuous interaction between the tyre and the road surface, which is noisier at higher speeds, and vehicle horns, leading to a fatigued body and spirit and triggering unpleasant feelings. In addition, this contributes to potential long-term risks of cardiovascular problems, such as heart attacks and hypertension. In general, prolonged exposure to high noise levels can affect work and educational environments, as it can weaken our overall cognition, communication, and attention. Conversely, the total burden of road traffic noise in the European Union - including direct costs and impacts, such as medical treatments and lost productivity - is estimated at 40 billion euros annually. Therefore, implementing effective measures to counter these adverse effects is essential to reducing road traffic noise pollution. In Europe, Member States are required to generate strategic noise maps every five years, and the accuracy and comparability of these maps depend on harmonised methods and reliable parameters. Differences in national road surface correction coefficients and uncertainties in propagation standards motivate a focused investigation that connects European-scale harmonisation with local, measurement-based validation. This work compares the CNOSSOS‑EU default values with the official national values published in Austria, Germany, and Finland, and demonstrates that inconsistencies in national coefficients can lead to significant differences in predicted exposure and affected population by road traffic noise, which in turn undermines the comparability and policy relevance of strategic noise mapping, it also reviews the 2024 updates of the ISO 9613-2, highlighting key parameters that are expected to improve the standard’s accuracy in modelling outdoor sound propagation, then it evaluates the performance of the CNOSSOS‑EU method alongside the ISO 9613‑2 standard in road traffic noise modelling using a case study from Hungary. This analysis not only supports the selection of appropriate modelling standards for similar traffic and environmental conditions but also positions the CNOSSOS‑EU and the ISO 9613‑2 within a broader international context, acknowledging their effective roles in environmental noise assessment. Finally, it emphasizes the importance of harmonized, transparent, and empirically validated methods for environmental noise management and policymaking.