Environmental Engineering Reference
In-Depth Information
Table 3.1
Sources of noise and levels of response (source: Defra from BRE National Noise Incidence
Survey 2000 (England and Wales))
Source
Per cent
respondents
reporting
hearing
Per cent respondents bothered, annoyed or disturbed
To some extent
Moderate
Very or
extremely
Road traffic
84
40
22
8
Aircraft
71
20
7
2
Neighbours/other people
nearby
81
37
19
2
Trains or railways
36
6
2
1
Building construction or
road works
49
15
7
2
Sports events
34
4
1
0
Between 1990 and 1999 the proportion of the population hearing traffic noise
increased by 6 points but the proportion said to be adversely affected by it at some
level decreased by a similar amount. This is in line with the more general finding
from the National Noise Incidence Survey which reports that noise levels on most
indicators have undergone a small reduction except background noise at night-time.
Nevertheless 54% of the UK population are estimated to experience average noise
levels which exceed the World Health Organisation's recommended daytime level of
55 dB(a). Eight per cent exceed the qualifying level at which remedial measures are
required by law if they arise from the development of a new road.
The population affected by aircraft noise in the vicinity of major airports is
subject to specific monitoring (reported in TSGB). At London Heathrow the number
subjected to levels causing disturbance has fallen by more than a half since 1990 (to
313,000) despite a 28% increase in air transport movements. Within this the number
experiencing higher levels of disturbance has fallen more sharply still. Similar trends
have taken place at the other major airports although the absolute numbers of people
affected is much smaller.
Noise experienced by pedestrians in the vicinity of main trafficked streets is not a
subject which has been monitored. Over time, despite the general increase in traffic,
the combination of improvements in vehicle technology, the redistribution of traffic
(especially HGVs) away from urban areas in general and town centres in particular will
have improved the noise environment in many places where pedestrians are concentrated.
However sudden high levels of noise experienced on pavements arising from the passage
of large and/or fast-moving vehicles, together with accompanying air turbulence, will add
significantly to the perceptions of danger noted in the previous section.
The redistribution of heavy traffic out of urban areas and its concentration into
fast-moving flows on motorways and the like is not however an unalloyed blessing
from an environmental point of view. The extensive envelopes of high noise levels
which surround them not only affect properties in the areas concerned but also blight
large tracts of countryside, greatly reducing their recreational value. In this context
rather than merely noting areas subject to traffic noise (the procedure followed when
assessing individual road developments) it may be more important to register their
effect in diminishing areas which retain the attribute of 'tranquility' which can be
considered a finite environmental resource (CPRE 2006). The extent and intensity of
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