First state-wide implementation of the CNOSSOS method in Luxembourg.

The 2015 update of the Environmental Noise Directive (END) annex II requires EU member states to use the Common Noise Assessment Methods (CNOSSOS) from 2018 onwards. In collaboration with the Environmental Administration of the Grand Duchy of Luxembourg, Stapelfeldt completed the first state-wide implementation of the CNOSSOS method in Europe. Featuring complex terrains, numerous bridges and a gradient of dense agglomeration and rural areas - Luxembourg provides an excellent opportunity to compare the CNOSSOS method to the formerly used NMPB method.

Model parameters

The main rationale for this study was to investigate potential result differences between the established NMPB and the new CNOSSOS method. Further, the numerical stability of the model was to be tested. The model included major roads only and contrary to the NMPB method, it is based on variable source input for emission data. Since statistics for hospitals and schools are calculated per complex in NMPB and per building in CNOSSOS, a direct comparison is not possible.

Results and implications

Parameter	NMPB	CNOSSOS	Relative Deviation
Average Calculation Time (h/sqkm)	0.6	1.45	+140.1 %
Area Lden (sqkm) > 55 dB(A)	203.3	214.9	+5.7 %
Area Lnight (sqkm) > 45 dB(A)	255.6	270.9	+5.8 %