Strategic noise map
The noise map shows on a plan noise levels for street sections. Therefore, it is a tool that lets you know the status of the city noise. In Europe there are the same guidelines for drawing it up. For example, noise levels are indicated by four different rates depending on the time period: Ld (daytime, from 7am to 9pm), Le (evening time from 9 to 11 pm), Ln (night period from 11pm to 7am) and Lden (weighted equivalent level day-evening-night).