Characterisation of wheel/rail roughness and track decay rates on a tram network

From the beginning of 2019, the new CNOSSOS-EU method shall be used for strategic noise mapping in application of Directive 2002/49/EC instead of national noise prediction methods. For the railway part, the operators are responsible for providing input data describing the different noise sources characterising the railway system. Concerning the rolling noise, the vehicle and the track have to be distinguished by providing specific transfer functions and wheel/rail roughness spectra. For conventional railways, default values are given in the CNOSSOS-EU method and national operators generally have experimental data at their disposal to evaluate these new input parameters. This is not the case for tram networks, for which very few measurements exist, notably concerning the wheel and rail roughness or the track transfer function. In 2018, Acoucité and IFSTTAR performed an acoustic test campaign on a French tram network in order to propose tram input data from pass-by measurements corresponding to various sites and vehicles. In this paper, the results concerning the direct measurements of wheel/rail roughness and track decay rates (a key parameter for the assessment of the track transfer function) are presented and discussed. The main differences with data corresponding to conventional railways are highlighted

Strategic Noise Maps of the Lyon and Grenoble agglomerations: Case study following the new CNOSSOS-EU calculation method and the inclusion of the health impact of noise

International audienceDirective 2002/49/EC on the assessment and management of environmental noise requires Member States to establish Strategic Noise Maps (SNM) for transport (road, rail and air) and industrial noise. Since January 1<sup> </sup> 2019, SNM must use a unified calculation method: CNOSSOS-EU. This method was used for the computation of SNM of road noise in the Grenoble agglomeration produced in 2019. This case study presents an assessment of the impact of the changeover by comparing the results obtained with the new method and those obtained with the old method (NMPB2008) for the same territory, as well as the methodology used to make the input data used for both methods compatible and comparable (traffic type, vehicles, surface). The results of the SNM for the agglomerations of Lyon and Grenoble (3<sup> </sup> deadline) were also used for the assessment of the health impact of noise. This impact is presented in accordance with WHO recommendations, in terms of Disability-Adjusted Life Year (DALY), in anticipation of future requirements in Annex 3 of the Directive

Association between transportation noise exposure ans hypertension risk in the french E3N cohort

International audienc

Lockdown during COVID-19 pandemic: impact on road traffic noise and on the perception of sound environment in France

Acoucité¹, centre of expertise in environmental acoustics and observatory of the sound environment, has investigated the changes in sound environment and its perception during the French lockdown period. The approach adopted is multidimensional, since it combines long-term acoustic measurements, large area noise mapping, as well as the study of sound perception self-reported by population sample through an on-line structured questionnaire. Data from 21 continuous sound monitoring stations² were analysed for the entire lockdown period in five conurbations in the south of France and compared to typical values in the “normal” situation (before lockdown) in order to quantify the reduction in terms of sound levels. Reductions from 4 dB to 6 dB (Lden) were observed for monitoring stations with highly dominant road noise. These results were used to obtain new Strategic Noise Maps for road noise (corresponding to the lockdown situation) for the conurbations of Lyon and Grenoble. The impact of such reductions in terms of noise exposure of their inhabitants was thus assessed. An estimation of the impact on health effects in comparison with the “normal” situation (Strategic Noise Maps “Round 3 CE-DE-2002”) was also carried out. This estimation considers a scenario where the above level reductions (4 to 6 dB) would take place in the long-term. An on-line perception questionnaire was available during the lockdown period with the aim of gathering information on the way that the changes in sound environment were perceived by people all over France and ended up with more than 3000 respondents. This paper reports the main findings of the study in terms of acoustics and sound perception

Association between transportation noise exposure and type 2diabetes risk in the French E3N cohort

International audienc

Association entre l'exposition au bruit et le risque de maladies cardio-métaboliques (diabète de type 2, hypertension artérielle ou maladie cardio-vasculaire)

Introduction : L’exposition au bruit semble être associée à un risque de développer une maladie cardio-métabolique (MCM) : hypertension artérielle (HTA), diabète de type 2 (DT2) ou infarctus du myocarde. Cependant, il existe peu d’études en France qui explorent cette association, et celles considérant les marqueurs de risque cardio-métaboliques (comme la tension artérielle, la glycémie ou le rythme cardiaque) sont peu nombreuses à l’étranger et inexistantes en France. C’est la raison pour laquelle le projet BROUHAHA a été mis en place. Objectifs : Le volet A de BROUHAHA vise à évaluer l’association entre l’exposition au bruit et le risque de développer une MCM. Le volet B a pour objectif d’évaluer l’association entre l’exposition au bruit à court terme et les variations des marqueurs cardio-métaboliques. Méthodes : Volet A : Dans une sous-cohorte de 22 000 femmes de la cohorte E3N (Étude Épidémiologique auprès de femmes de l'Éducation Nationale), l’estimation de l’exposition au bruit sera calculée à partir des cartes stratégiques de bruit au domicile de chaque femme ayant résidé en Île-de-France (IdF) ou en Auvergne Rhône-Alpes (AuRa) entre 2000 et 2018, puis mise en relation avec le risque de développer une MCM. Volet B : Une étude pilote sera menée auprès de 120 hommes et femmes de la cohorte E4N-G2 (enfants des femmes E3N), en bonne santé, habitant en IdF ou en AuRA. L’exposition au bruit sera évaluée pendant 7 jours à l’aide d’un dosimètre et de l’application NoiseCapture. Les marqueurs cardio-métaboliques (activité physique, sommeil, rythme cardiaque, tension artérielle et glycémie) seront mesurés avec un bracelet, un tensiomètre et un capteur de glycémie connectés. Le contexte dans lequel s’inscrit ce projet BROUHAHA ainsi que le protocole de ces deux volets seront présentés