2.4.4     Noise measurements

2.4.4.4  Noise maps

The presentation of noise maps is newly laid down in the draft of DIN 18005 Part 2, which is to standardize the presentation.

The results of the Traffic noise mapping Stuttgart (1998) are to be presented in the following as an example of a traffic noise map predominantly based on measurements.

A sound level meter which allowed for the determination of the exceedance levels L₁, L₅, L₁₀, L₅₀, L₉₀, L₉₅ and L_eq was used for the measurements.

A preliminary study clarified the necessary measurement periods in the proximity of roads required for an adequate representation of the noise level at a particular type of road and for the reduction of the measurement period.

The noise measurements were carried out at road measuring points by the side of the road on weekdays. In accordance with the measurement guidelines, holidays and days with adverse weather conditions (snow, rain, strong wind) were excepted. The noise levels for roads where no measurements were conducted were determined through comparisons by analogy with adequate roads.
 
The results are available (in German) at: http://www.stadtklima-stuttgart.de/index.php?laerm_db

Table 2/2 gives the final results of the road measurements as frequency distributions.

Table 2/2: Total frequency of lower deviations of the noise level categories (TRAFFIC NOISE MAPPING STUTTGART, 1998)

The frequency distribution of the noise level categories (see fig. 2/14) clarifies the traffic noise pollution in Stuttgart, which is typical of big cities. Average levels of less than 50 dB(A) occur rarely at daytime and are restricted to narrowly defined purely residential areas without through traffic.