The Mayor's Ambient Noise Strategy - Greater London Authority

The Mayor’s Ambient Noise Strategy Mayor of London 93
4A.71 Transport for London has examined options for noise mapping of the
Transport for London Road Network (see pilot map Figure 14 below).
The Government has commissioned road traffic noise mapping of
London as part of work on national ambient noise strategy. 3
Constructive participation by Transport for London in national work will
help to ensure that it is as useful as possible for London-level and
borough purposes. Noise mapping should be used as a tool, not just for
assessing population exposure to noise, but also, as far as possible, for
testing the effectiveness of potential mitigation measures. Available
noise mapping models do not contain parameters representing every
possible way of reducing noise, so standardised or measurement-related
adjustments may be needed.
Figure 14 Pilot road traffic noise exposure map (L Aeq 18 hour
)
dB L Aeq 18 hour
over 80
75 - 80
70 - 75
65 - 70
60 - 65
55 - 60
50 - 55
45 - 50
40 - 45
35 - 40
0 - 35
source:
WS Atkins 2001: Noise mapping in London - Options for progress
4A.72 Many measures which would reduce the types of noise which annoy
people would not be reflected in ‘averaged’ ambient noise mapping. Such
a map is only one part of the process of understanding urban traffic
noise, and improving people’s conditions (see Chapter 5). Physical
measurement of noise in sample areas can identify changing noise profiles
over the day, evening and night, and at weekends, particularly where the
contribution of different sources changes. A noise monitoring network,
including a sample of sites at which periodic measurements are made over
a period of years, would provide comparisons with noise mapping, and
improve understanding of changes in noise over the day and week.
4A.73 Transport for London, and other highway authorities in London, should
seek to record where substantive noise-reducing measures have been
taken, their cost, and, where appropriate, information on effectiveness.
Analysis on a case study basis should be carried out to help adjust and
improve performance. The Government should fund monitored trials of
the effectiveness of targeted noise reduction projects and programmes in