The City of Helsinki’s latest noise mapping project was completed in 2017. The noise mapping project involved the calculation of noise levels caused by highways, main and collector roads, railways, and tram and metro traffic, as well as the numbers of residents exposed to noise for each form of transport. Road traffic is the most significant cause of disruptive noise in Helsinki. On the basis of the noise mapping project, Helsinki’s Noise Control Action Plan for 2018–2022 is currently being drawn up. Noise mapping projects and noise control action plans are revised every five years.
The mapping projects are carried out in accordance with both the EU’s Environmental Noise Directive and national regulations. The calculation methods and results for each differ from each other. The results of Helsinki’s 2017 noise mapping project carried out in accordance with the EU’s Environmental Noise Directive cannot be directly compared with national noise level reference values.
The objective of the Environmental Noise Directive is to gather comparable information on the noise situation in EU member states. The results of the national noise mapping project are to be used for purposes such as noise situation monitoring and land use planning.
EU noise mapping
The mapping project was carried out in accordance with the EU’s Environmental Noise Directive, and previous noise mapping projects were carried out in 2007 and 2012. According to the findings of the project, approximately 26% of Helsinki residents live in areas where the day-evening-night noise level of road and street traffic exceeds 55 dB. Approximately 1% of residents are exposed to railway traffic noise, 4% to tram traffic noise, and 0.5% to metro noise. Approximately one in a thousand Helsinki residents live in the area exposed to noise from Helsinki-Malmi Airport. Industry does not cause significant levels of noise in residential areas.
A new European calculation method was used in the noise mapping report completed in 2017, due to which the number of residents exposed to noise differs significantly from that in previous mapping projects. The new method for calculating the number of residents exposed to noise takes into account that some residents’ homes are located on the quieter façades of buildings. For this reason, the number of residents exposed to noise is now approximately half of the number recorded five years ago.
National noise mapping
In Finland, environmental noise is regulated based on the government decision on reference values for noise levels (993/1992). The reference values concern average daytime and night-time noise levels LAeq. According to the national noise mapping project, approximately one third of Helsinki’s total land area lies within areas exposed to traffic noise. In terms of residents, 37% live in areas where the noise level of road and street traffic exceeds the daytime reference value level of 55 dB.
The number exposed to road and street traffic noise has increased 4% from the previous mapping project carried out in 2012. The results of the mapping project are highly consistent with those of the previous project in terms of road and street traffic, once population growth is taken into account. The number exposed to highway noise has fallen 8% since 2012. This result can be explained both by noise control measures implemented and the use of more detailed background information for the calculations.