Harmonized Europe-wide road traffic noise modeling using CNOSSOS-EU: beyond END and agreement analysis with national models

In Europe, lack of consistent noise data has hampered large-scale epidemiological studies and disease burden assessments related to noise in Europe. This study addressed these limitations by developing and evaluating a Europe-wide noise model using CNOSSOS-EU, a standardized noise calculation framework in Europe. We implemented the CNOSSOS-EU model using harmonized input data, including traffic flow estimates for all roads. We compared our noise estimates with national estimates from three countries and one city in a agreement analysis. As a proof of concept, we estimated noise levels at the noisiest façade points of 102,560 randomly-selected buildings across Europe and 14 million buildings in the cohort study areas. Overall, plausible day-evening-night levels (Lden) were modelled at points with varying traffic flow on nearby roads. The Lden model estimates showed moderate correlations with national noise models in Switzerland, the Netherlands, and the United Kingdom (Pearson's cor = 0.52-0.77) but a lower correlation in Stockholm County (0.39). Most randomly-selected building façade points (62%) had traffic flows on nearby roads below the END modeling threshold, with substantial noise variability. Because the input traffic flow estimates on residential roads explained little variability, noise estimates should be applied with caution where residential roads dominate the noise exposure. While high-quality national models remain gold-standard and preferable for health analysis and impact assessments where available, our Europe-wide model offers standardized estimates across countries and expands beyond END maps. Both Europe-wide and national estimates should be considered in sensitivity analyses to assess potential differences in estimated health effects. The resulting noise estimates may further facilitate our understanding of noise-related health effects and disease burden at a broader scale in Europe for countries lacking national noise models.