Strategic noise maps of 4th deadline made in 2022

In accordance with European regulations, noise maps are to be developed for large transport infrastructure and large agglomerations. They usually represent by colour codes, exposures to ambient noise (expressed in decibels). Strategic noise maps made in 2022 enable diagnosis on the four sources following: road noise, rail noise, air noise and industrial noise. noise maps are involved in the development of Environmental Noise Prevention Plans (EPPs). Noise measurements are carried out by sensors placed 4 m above the ground. Calculations are performed via acoustic modelling software, after the data have been previously formatted in order to obtain acoustic conformity. The noise levels and exposure statistics obtained follow calculation standards defined with the aim of maintaining consistency at national or even European level. Ln (Level Nigh) The value of the noise index Ln, expressed as A-weighted decibels (dB(A)), represents the level of noise exposure at night. It corresponds to the average sound level determined over all night periods of a year. The Lden (Level Day Evening Night) The value of the Lden noise index, expressed as A-weighted decibels (dB(A)), represents the level of total noise exposure. It results from a weighted calculation taking into account the average noise levels determined over a year, for each of the three periods of the day, i.e. the day (between 6 am and 6 pm), the evening (between 6 pm and 10 pm) and the night (between 10 pm and 6 pm). The weightings applied for the calculation of the Lden index are applied over the evening and night periods in order to achieve a better representation of the discomfort perceived by local residents throughout the day. The data is presented in TIFF format, it is a format for digital image, to open and manage it you have to have an application such as Adobe Photoshop.