appendix a - Velocidade

LAFmax, 5% [dB(A)]
90
85
80
75
70
65
60
Heavy
Light
30 40 50 60 70 80 90 100 110 120 130
Speed [km/h]
34
The effect of speed on noise, vibration and emissions
from vehicles
May 1998
C:\eget\exceln\noise\Predic_LAEvsSpeed.xls_sheet2
Fig. 7 The noise-speed relations for ”maximum noise levels” (those levels which 5 % of
vehicles exceed during their passage) used in the Nordic traffic noise prediction model.
Adapted from TemaNord, (1996).
It is debatable whether one should consider these maximum levels or not, since it is only in
the Nordic countries in which this measure is used. It would also raise the question, which of
the two groups of results one should consider (and which are only marginally different).
Consequently, the calculations for "maximum noise levels" are not presented.
Another possible choice would have been the L10, i.e. the level which is exceeded 10 % of
the time. This has been used in the CRTN model in the UK. However, this measure is
probably going to be abandoned in an upcoming revision, and the Leq adopted instead. The
L10 measure is somewhere ”between” Leq and Lmax, although a little closer to the Leq.
Calculations based on L10 would give similar (but not identical) noise-speed relations as the
ones based on Leq.