Noise is a health risk

Noise is “amongst the most relevant environment and health problems, just behind the impact of air quality” (European Commission, 2014). Around 40% of the EU population are exposed to road traffic noise at levels exceeding 55 dB; 20% are exposed to levels exceeding 65 dB during daytime; and more than every third citizen is exposed to levels exceeding 55 dB at nighttime (WHO, 2013). Exposure to these noise levels does not only lead to high levels of annoyance, but also to known health risks.

The environmental noise directive (END)

To tackle noise, the European Parliament and Council adopted the Environmental Noise Directive 2002/49/EC (also known as END) in 2002. It aims to “define a common approach intended to avoid, prevent or reduce on a prioritized basis the harmful effects, including annoyance, due to the exposure to environmental noise” (European Commission, 2014). To monitor noise, EU member states are therefore requested

  • to draw up strategic noise maps for major roads, railways, airports and agglomerations every five years, starting in 2007;
  • to inform and to consult “the public about noise exposure, its effects, and the measures considered to address noise in line with the principles of the Aarhus Convention* ”;
  • to draw up action plans to reduce noise – limit values and measures are not predefined, but are at the discretion of the competent authority;
  • to develop “a long-term EU strategy” to reduce the number of people affected by noise (European Commission, 2014).

Consequently, maps are the major instrument for assessing noise in European cities, for informing the public and for formulating action plans. These maps present the harmonized noise indicators Lden** (day-evening-night equivalent level) and Lnight (night equivalent level) as colored fillings of the equal-noise contours (also isophones).

Thus, color is the major way of representation. An appropriate color scheme facilitates a straightforward interpretation of noise maps. 

From a cartographic perspective, however, the prevalent color schemes for European noise maps are not suitable. In Germany, the default scheme is specified in DIN 18005-2. A review can be found here.


 Sources and Footnotes

* The Aarhus Convention, adopted in 1998 by the United Nations Economic Commission for Europe (UNECE), gives everyone the right to access environmental information that is held by public authorities, the right to participate in environmental decision-making, and the right to review procedures to challenge public decisions.
** Lden is the A-weighted long-term average sound level for daytime, evening and nighttime (7 am to 7 pm, 7 pm to 11 pm, 11 pm to 7am, with possible offsets for certain countries). An extra 5 dB is added for the evening level and 10 dB for the night level.

European Commission (EC), 2014. (accessed April 2014).
World Health Organization (WHO), 2013. (accessed April 2014).