A Review of Transport Noise Indicators

The different approaches to noise impact assessment adopted by the individual countries and the scientific community have led to the development of a certain number of indicators, mainly focused on specific transport modes. However, in practice, technicians and decision-makers alike may fail to identify the most appropriate indicators, if they have no specific expertise on environmental noise. This paper presents a review of the main transport noise indicators, both the general acoustic ones and those used for specific transport modes. A critical analysis of the strengths and weaknesses of these indicators is provided, as well as a section discussing the framework in which they work, and suggestions for their best use, aimed at assisting decision-makers to ascertain their role in the evaluation process of the transport systems. To this extent, a classification is proposed, supplemented by the DPSIR (driving forces, pressures, states, impacts, responses) approach, in an effort to assess the cause--effect relationship between society and the environment. Decision-makers will also gain insight into the prioritization of the use of the existing indicators in accordance to their own needs, as well as advice on the joint use of socioeconomic variables to fully support their decisions.