The implementation is divided into phases: In the first phase, the member states shall inform about major roads with more than six million vehicles a year, major railways with more than 60,000 trains per year, major airports with more than 50,000 movements per year and metropolitan areas with more than 250,000 inhabitants. In the second phase, these numbers are halved; only the criteria for airports remains unchanged. In the third and the following phases, the methods for calculation of the noise levels will change while the criteria remains unchanged.