The Traffic Noise Ordinance (16th Federal Immission Control Ordinance) (available in German) is applied to the construction or major alteration of public roads and railways. An alteration is "major" if a road is enlarged by one or several continuous lanes (the same applies to railway tracks) or if the rating level of a transport route increases by at least 3 dB(A) or to at least 70 dB(A) during the day and at least 60 dB(A) during the night as a result of significant building measures. An alteration is also "major" if an existing level of traffic noise of at least 70 dB(A) during the day or 60 dB(A) during the night is still increased through significant building measures (this does not apply to commercial areas).

Modified traffic light circuits or smaller building measures, e.g. the construction of a traffic island, represent no significant building measures in the meaning of the ordinance.

The calculation of the rating levels is based on RLS-90 and Schall 03 for railways. The ordinance refers to special methods of calculation developed by the German Federal Railways (Akustik 04) for extensive railway installations on which cargo trains are assembled or disassembled on a large scale.

The Traffic Noise Ordinance determines within its scope the immission limit values listed in table 3/2 to protect the neighbourhood from harmful environmental impacts caused by traffic noise. If the limit values are exceeded, there is a right to noise protection measures, predominantly active measures like noise protection walls and barriers. If this is not possible or if "the costs of the protective measure would not be commensurate with the desired protection goal" (§ 41 (2) of the Federal Immission Control Act), passive noise protection measures (e.g. soundproof windows) must be taken at the concerned buildings. Nature and extent of the necessary sound-proofing measures for rooms requiring protection in construction works are determined by the Ordinance on Road Noise Protection Measures (24th Federal Immission Control Ordinance).

Table 3/2: Immission limit values from the 16th Federal Immission Control Ordinance in dB(A)

If the protected use is restricted to daytime or nighttime, only the limit value valid at this time is to be applied.

What has to be considered in the context of railway traffic is the fact that the characteristic features for rail-borne traffic with the usual deduction of 5 dB is not to be applied to railways on which cargo trains are assembled or disassembled on a large scale.