Thursday 26 March 2015

Volume III - Report (E. Environmental Criteria)





E. ENVIRONMENTAL CRITERIA


I    THE ENVIRONMENT

II   NOISE

III  AIR POLLUTION

IV   VIBRATIONS

V    ECOLOGICAL CRITERIA

VI   VISUAL INTRUSION

VII  OPEN SPACE



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I  THE ENVIRONMENT


1. WHAT IS ‘THE ENVIRONMENT’?

1.1 The Terms of Reference

The Inquiry is enjoined to consider a number of
road options ‘with particular reference to' the:

"Environmental and social impacts of
any proposal, especially effects on
parklands and housing, and the
effects of through traffic on
residential areas."

1.2 The Way in Which Other Instruments Define ‘Environment’

The Commonwealth Act, the Environmental Protection
(Impact of Proposals) Act 1974 (1) contains the
following definition of 'the environment' (2):

"'Environment' includes all aspects
of the surroundings of man, whether
affecting him as an individual or
in his social groupings, and
"environmental" has a corresponding
meaning."

The definition of "environment" in the New South
Wales Planning Legislation, the Environmental Planning
and Assessment Act
(3) is in identical terms.

The Simblist Inquiry (4) was called upon to examine
‘the environmental impact' of certain projects which
were planned for Port Botany. It defined the term
as follows (5):

"The word "environment" has been taken
to mean the existing total situation
as at a given time, including all the
physical surroundings, social patterns
and ecology of a given area. "

1. Act No. 164 of 1974.
2. Section 3.
3. Section 4.
4. Botany. Bay Port and Environment Inquiry, November,
   1976.
5. Botany. Bay Port and Environment Inquiry Report,
   page 14.

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The 'environment' is everything around us. It is
much more than parks and trees, although certainly
they are a precious part of it. It is the shopping
centres, the streets, the air we breathe, the level
of noise, the traffic, and interaction with one's
neighbours.


2. CHANGING ATTITUDES TO THE ENVIRONMENT

2.1 Attitudes Can Change Rapidly
The opening words of the County of Cumberland
Planning Scheme Report
in July, 1948 portrays a
different world (6):

"This is a planning scheme for a vital
and prosperous region, for the second
white-city of the British Empire, for
the other towns of the region and the
broad acres between them."

The sun has now set upon the British Empire. It
would be considered unacceptable today, even racist,
to refer to Sydney as a 'white-city'.

The word ‘environment’ had barely surfaced before
the 1960s. Suddenly it was on everyone's lips. The
politicians quickly followed with Departments which
were concerned with the environment. Legislation
came soon thereafter.

Nor is this a fad to be derided. Changes have taken
place which are hard to ignore. Sydney is surrounded
by a skirt of brown-smog. People begin to wonder
whether it may be having some insidious effect upon
their lungs and upon the health of their children.

And there are small things besides. Their impact
upon community consciousness is nonetheless substan-
tial. People were fond of certain trees which lined
the beaches at Manly and Bondi (7). Gradually they
died. Their death was attributed to detergents
introduced by man into his environment.

6. County of Cumberland Planning Scheme Report, page 1.
7. SPCC Annual Report 1975, pages 31-32.

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And then there is the phenomenon with which we are
all familiar. People have taken to the streets
boldly proclaiming a certain joy in physical fitness.
Having taken that step it is difficult to ignore air
contaminated by fumes (where that is encountered) or
an environment bereft of trees and grass (where that
occurs).

2.2 The So-called ‘Freeway Revolt’

There were a number of events overseas which soon had
their counterpart in Australia. Public opinion forced
the abandonment of the Embarcadaro Freeway in San
Francisco. In Toronto the Spadina Expressway was
halted despite the expenditure of $150,000,000 on
land purchase, earthworks and even overpass structures.
Structures were simply left dangling in mid-air.

In Australia each capital city has commissioned a
Transportation Study. The Adelaide Transportation
study was completed in 1968. The Melbourne Metropolitan
Transportation Study was published in 1969. The
Perth Regional Transportation Study appeared in
1970 and the Sydney Area Transportation Study was
published in 1974.

The SATS Report described the fate of the Adelaide
Study, and what then appeared to be the fate of the
Melbourne Study, in these words (8):

"Most of the Adelaide plan is under-
wraps, if not abandoned. Implementa-
tion of Melbourne’s plan has been
deferred due to downward revisions
of the forecast city population and
opposition to the freeways. Never-
theless 150-200 of the projected 307
miles of freeways will probably be
built and the underground is to be
built."

That assessment, in the event, proved to be inaccurate.
The public's reception to the Melbourne plan, and to the
Sydney Plan which followed, is described by NAASRA in

8. SATS Volume 2, Chapter VIII, page 9.

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These terms (9):-

“Until recently Australians regarded
the freeway protest movement as a
North American aberration which
could not occur here. But in recent
years this illusion has been rudely
dispelled, particularly from experiences
in Sydney and Melbourne...The protest
movement has influenced governments at
Federal, State and local levels.
Recently it had resulted in union
green-bans, physical disruption and
even sabotage designed to halt
demolition to propertied, a necessary
preliminary to construction, and the
construction itself.”

The ‘protest movement’ so-called is simply one
manifestation of community attitudes. It may or
may not represent the community view. It under-
lines the importance of public participation and
the need for informed debate on matters of public
concern.

9. NAASRA “Community and Environmental Aspects of
   Urban Highway Proposal” 1976, pages 1-2.

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II  NOISE

1. DESCRIPTION OF NOISE

1.1 Definition of Noise

Noise is somewhat glibly described as unwanted
sound. It is commonplace nowadays to hear the
expression 'noise pollution’, emphasising that
the sound is unwanted and is perceived as
'contaminating' the senses. It is defined by
the Left Handed Dictionary as 'audible grime' (10).

To state the definition is to immediately confront
the problem that noise is, by its nature, subject-
tive. A person whistling may create music to his
own ears and noise to the ears of someone nearby.
Yet that bystander may attend a rock concert and
be exposed to sound levels which, to another's ears,
is deafening.

What is it about certain sounds which enables us to
say that they are "noise"? What means are available
to measure sound levels? what steps can be taken to
combat "noise”?

1.2 The Decibel Unit (dB(A))

Sound or noise consists of pressure waves which
can be expressed as units of pressure. A commonly
used unit is the decibel (dB).

The decibel is not adequate as an objective measure
of noise (11). The decibel ranks noise according to
the total sound pressure level. It takes no account
of the human ear's relative difficulty in perceiving
low and high frequency levels. A scale has been
developed, known as the "A”-Weighted Scale (dB(A)),
which endeavours to reproduce the frequency response
of the human ear by ranking sounds according to their
relative loudness.

10. Left Handed Dictionary, page 157.

11. "Effects of Traffic and Roads on the Environment
    in Urban Areas” O.E.C.D., page 13.

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The dB(A) scale is a logarithmic scale. An increase
of 10 dB(A) effectively doubles the relative
loudness. The concept can be illustrated in the
following way:

FIGURE 5.

THE DECIBEL SCALE.




Source: NAASRA "Roads and Traffic Noise", page 2.


Other typical noise levels are:
  • ticking of a watch held to the ear  20 dB(A)
  • inside a quiet dwelling late
    at night                            35 dB(A)
  • rustling of leaves                  50 dB(A)
  • vacuum cleaner (at three metres)    69 dB(A)
  • ringing alarm clock (at one metre)  77 dB(A)
  • a Boeing 727 jet landing (at three
    hundred metres)                     86 dB(A)
  • heavy city traffic                  92 dB(A)
  • a Boeing 727 jet on take off (at
    three hundred metres)              102 dB(A)
  • unsilenced jackhammer              107 dB(A)
  • Thunder                            110 dB(A)
  • threshold of pain                  140 dB(A)


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An illustration of these levels, and the human
response to each situation, is to be found in
the Annual Report of 1978 of the State Pollution
Control Commission. The diagram from that report
is reproduced here:

FIGURE 6.

NOISE LEVELS.




1.3 The Context in Which the Noise is Made

Human response to noise is much more than simply
a response to loudness, though certainly that is
important. The response is conditioned by many
factors and the inter-action between those
factors.

First, there is the context in which the noise
is made. The context involves an appreciation
of the character of an area, and the background
or ‘ambient' noise levels. The ‘background noise’
is the complex inter-action of all noises in the
area. One would expect differences between, say,
an industrial and a residential area.

The community living within an area will become
habituated to the background level of noise.
Intrusive noise, therefore, is noise which
exceeds the background noise level by a certain
margin. Again the margin will vary, depending
upon the nature of the area and the time of day.

Secondly, the response is likely to vary depending
upon the nature and duration of the intrusive noise.
It may be noise of an impulsive character, such as
hammering or riveting, or the whine or screech of
a machine. It’s very intermittency may make it
more obtrusive, and hence more objectionable.

Thirdly, the contrast between the intrusive noise
and the background noise is liable to make it
more or less objectionable. If it can be easily
distinguished from the background noise, it may
increase the irritation felt by the listener (a
dripping tap). Conversely the irritation may
abate where unpleasant sounds (intrusive noise)
can be masked by the presence of pleasant
background noise ('background music') (12).

Fourthly, the noise may be the more offensive where
it is perceived as unnecessary or avoidable.

12. The Cooks River Valley Association, Noise and
    Air Pollution Report by Dr. Mudford, page 36.

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Finally, people are more tolerant of natural
sounds, such as the roar of the surf, or the
wind in the trees, than artificial sounds (e.g.
a pile driver or jack hammer).

These are but a few of the many factors which
condition human response to noise. It is
interesting to note in passing the definition
of "offensive noise" which appears in the Noise
Control Act, 1975:

"Offensive noise is noise which, by
reason of its level, nature, character
or quality, or the time at which it
is made, or any other circumstances,
is likely to be harmful to, offensive
to or to interfere unreasonably with
comfort or repose of persons.”


2. TRAFFIC NOISE

2.1 Traffic Noise and the dB(A) Scale

Traffic noise constantly fluctuates. Noise and
relative silence will be inter-dispersed at
irregular intervals. This may itself be a cause
of annoyance. A single dB(A) figure cannot
adequately describe the noise fluctuations.

Some description reflecting variability over
time is, therefore, necessary. It has been found
convenient to use the following terms applied to
any convenient period of time e.g., one hour,
eighteen hours, twenty-four hours etc.

  • L10; the sound level in dB(A)
         exceeded for ten percent
         of the time
  • L50; the sound level in dB(A)
         exceeded for fifty percent
         of the time; the mean
         level of sound.
  • L90; the sound level in dB(A)
         exceeded for ninety percent
         of the time.

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The L10 reading is taken as a good approximation
of ‘intrusive noise’, whereas the L90 reading is
said to represent, to an acceptable degree of
accuracy, the 'background noise’.

The level of noise generated by traffic is due
principally to the following:
  • the total traffic flow;
  • the proportion of heavy vehicles;
  • the vehicle operating environment
    including the road surface.

2.2 The Contribution of Heavy Vehicles

Traffic noise grows rapidly with size of flow.
At moderate and high volumes it changes only
slowly as the amount of traffic increases.
Hence, traffic noise rises by only 3 dB(A) for
each doubling of traffic flow, as demonstrated in
the following graph:


FIGURE 7.
NOISE EXPOSURE AT 30 METRES FROM ROAD
CARRYING TRAFFIC INCLUDING 20% HEAVY
VEHICLES AT 75km/HOUR



Source: Report of the Urban Motorways Project Team,
        page 37.


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The Options being considered by this Inquiry will
cause reductions in the traffic flow in certain
areas, whilst noise, or increased noise, will be
introduced into other areas. The reduction of
traffic flow may occur in that part of the graph
where the curve is relatively flat, so that there
will not be a perceptible decrease in noise. It
is said the building of a road through a quiet
valley, where no road presently exists, will
introduce a source of noise, obtrusive and objec-
tionable to the surrounding population, without
any corresponding benefit, through reduction of
noise, along those roads in which traffic flows
may be reduced. The claim will be examined when
the options are evaluated.

Any reduction or increase in noise less than 3
decibels is unlikely to be perceived even though
the traffic flow may have swelled considerably
(or reduced considerably). That is not to say
that one can afford to ignore changes in noise
levels of less than 3 decibels. The Leitch
Committee Report states (13):

"It is true that on average that people
do not distinguish between individual
noise events of less than 3 dB(A)
difference. Thus it might be difficult
to say which of the two aircraft, one
of which was actually 2 dB(A) noisier
than the other, seemed noisier if they
took off several minutes apart. But it
is not necessarily valid to extend this
observation when the units change from
peak dB(A) (single events) to aggregate
L10 dB(A) over a significant period of
time. A noise increase of 3 dB(A) L10
is approximately equivalent to a doubling
of traffic volumes. We believe that many
people would notice the increase in noise
long before the traffic passing them doubled
.”
                               (emphasis added)

13. Report of Advisory Committee on Trunk Road
    Assessment 1977, page 111.

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Heavy vehicles contribute to highway noise in
two distinct ways. First, their presence in the
traffic stream can operate to slow the traffic,
and the noise generated at slower speeds by all
vehicles is likely to be higher than at higher
speeds. Secondly, and more importantly, the
vehicles themselves operate at high noise levels,
so that even a small percentage of heavy vehicles
has a disproportionate effect upon traffic noise
levels.

In a paper prepared for the Commission of Enquiry
into the N.S.W. Road Freight Industry
, Associate
professor A.B. Lawrence and Mrs. Burgess record
the results of a Survey designed to indicate the
contribution of cars and trucks to maximum traffic
noise levels (14).
  • At the Wollongong by-pass trucks
    constituted 14.5 Percent of the
    vehicle flow over an 18 hour
    period. Yet they contributed
    52% of the noise which could be
    regarded as unacceptable.
  • At the Princes Highway, Fairymeadow
    medium and heavy trucks constituted
    8% of the 18 hour traffic flow.
    They contributed 46% of the noise
    which could be considered unaccep-

    table.
The Commission in its Report stated (15):

"Community dissatisfaction has some
correlation with the percentage of
heavy vehicles in the traffic stream
,
rather than with some general measure
(e.g. L10) of noise level, probably
because their noise is more intrusive.”

14. Commission of Enquiry into N.S.W. Road Freight
    Industry, Volume VI, Supplementary Paper 6.0,
    pages 10-11.
15. Commission of Enquiry into N.S.W. Road Freight
    Industry, Volume IV, page 5/33.

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The Inquiry, therefore, must concern itself with
the number of vehicles using the road system and,
more especially, the number of trucks using
particular routes.

2.3 The Attenuation of Noise With Distance

Traffic noise diminishes as it spreads. The degree
of noise exposure for people living in the vicinity
of a road will depend upon:

  • the distance from the road
  • the nature of the surface between
    them and the road i.e., whether
    it is soft or hard surface
  • whether there is any barrier or
    shield in between (such as some
    residence or structure).

Dealing with each of these factors in turn, the
attenuation with distance can perhaps best be
demonstrated by means of a graph.

FIGURE 8.

ATTENUATION WITH DISTANCE
OVER HARD SURFACES



Investigations were carried out by the Royal
Automobile Club of Victoria after the construction
of the Tullamarine Freeway. That freeway connects
the city of Melbourne to the Tullamarine Airport.


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They state (16):

"It is generally found that residences
located outside a distance of 400 feet
from the freeway pavement do not
experience significant noise distur-
bance. People living within 300 feet
and in full view of the freeway, with
little or no intervening shielding
structure between themselves and the
freeway carriageways generally
experience a strong reaction to the
noise environment
. Hardship is caused
in the form of sleep interference, and
the need to keep windows and doors
closed and interference with other
activities such as watching television.”
                                (emphasis added)

The graph (Figure 8) refers to attenuation over
a 'hard surface'. The attenuation is likely to
be greater where it is over a soft or absorbent
surface, such as grass or foliage. Some of the
options (the Cooks River and South Western Options)
but not others (the Bexley Road option) contemplate
grassed areas on either side (subject to the
provision of a bitumen-surfaced bikeway).

Sound is deflected by obstacles in its path.
Houses are a very effective barrier, particularly
when terraced or built closely together. Property
in the second row away from the road, unless taller
than the first, will seldom be exposed to high
noise levels (17). Trees, especially lightly
foliaged Australian trees, (18) offer little
protection from traffic noise. However, they can
serve to mask the highway to provide "a pleasant
visual screen" (19) so that the noise is less
obtrusive or objectionable even though it may not be
materially reduced. Very often the nature of the
topography, makes shielding impossible. The


16. Page 2 “The Effect of Traffic Noise from
    Freeways” R.A.C. Victoria (1972) .
17. Report of the Urban Motorways Project Team
    to the Urban Motorways Committee, page 39.
18. Page 36, Dr. Mudford report.
19. Page 36, Dr. Mudford report.

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Investigating Team into the effects of noise arising
from the Tullamarine Freeway made the following
observation (20):

"Hillside residential development over-
looking the freeway causes more houses
to be exposed without adequate shielding
and consequently noise disturbance will
be more widespread."


3. EFFECTS OF NOISE

3.1 The Adjacent Land Use

The effect of noise will vary depending upon the
surrounding land use. Obviously it is important
to examine the nature of adjacent land uses when
considering the introduction of an additional
noise source. Certain land uses are rather more
sensitive to noise than others. The following
submission was made by the Beverly Hills North
Parents' and Citizens' Association (21):

"The staff of the school already complain
at the level of noise experienced in
classrooms close to King Georges Road
and (further) noise will reduce the
effectiveness of teaching due to the
interruption to the fragile concentra-
tion of the young pupils who attend this
school.”

There are hospitals and schools scattered through-
out this area, as well as substantial residential
areas. The effect of the options on each must be
carefully judged.

3.2 The Insulation from Noise Within the Home

The external walls of a home provide an effective
shield to noise. The point is best made by a
simple illustration:

20. Page 7 of "The Effects of Traffic Noise from
    Freeways" R.A.C. (1972).
21. S.K/C 787 Beverly Hills North Parents’ and
    Citizens' Association.

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FIGURE 9.

REDUCTION OF NOISE ENTERING BUILDINGS.



Source: NAASRA "Roads and Traffic Noise", page 6.


Noise levels are likely to be reduced 45 dB(A) if
the outside cladding of the home is brick veneer.
Timber provides less effective insulation reducing
noise by 30 dB(A). Homes immediately adjacent to
the proposed routes differ in their construction,
some being made of brick, and others of timber or
fibro.

The diagram underlines the effectiveness of windows
as a means of insulation. A closed window will
reduce sound levels by between 15 and 25 dB(A). An
open window brings about a reduction of only 10 dB(A).
The experience in Melbourne with the opening of the
Tullamarine highway is again relevant. The
investigation was conducted by survey. The
following appeared (22):

"15 replies indicated that special care
was taken to keep the house closed by
drawing external sun blinds, having
heavy drapes on the windows and keeping
windows and doors closed at all times.
These measures in turn caused ventila-
tion problems."

In the Sydney climate, especially in summer, the
need to close windows, and keep them closed, is a
serious impediment.

22. Page 6 "The Effect of Traffic Noise from
    Freeways” R.A.C. (1972).

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3.3 Noise as a 'Destroyer of Residential Amenity’

The Urban Transport Study Group of New South Wales
in its Central Industrial Area Study (23) surveyed
residents and local councils within the Central
Industrial Area. Noise, amongst other issues, was
identified as an important problem within the area.
The City of Sydney Residents Action Committee
(C.O.S.R.A.C.) has stated that "noise is the most
important destroyer of residential amenity in the
City" (24).

The Planning and Environment Commission in 1978
conducted an extensive survey of the Botany sub-
region. The survey included many of the suburbs
from which submissions have been made to this
Inquiry. Public meetings were held, and local
councils were interviewed. Increase in noise
pollution was described as 'the most significant
factor mentioned at public meetings’ (25).

In the present Inquiry almost every submission
mentioned noise pollution. Likewise, the evidence
given in the public hearings emphasised the
objectionable nature of noise, and the need for
steps to be taken to remove or diminish it.
Typical of the submissions is that from a resident
in Forest Road, Bexley (Mrs. McKenna) where she
states the following:

"The noise is relentless from 6 a.m. to
nearly midnight. Our bedrooms are
situated to the front of our house and
to go to bed at a reasonable hour is
futile, so we never get a decent night's
sleep. The noise is a bit less to the
rear of the house, but one is still
troubled by it, even there. My children
do their studying with their ears stuffed
with cotton wool to block out the noise,
so they can concentrate!”

23. Urban Transport Study Group of N.S.W “Central
    Industrial Area Study”, June, 1977, page (i)-(v).
24. P.E.C. publication “Inner Areas", page 86.
25. P.E.C. "What You Said”, page 31.

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It is trite to conclude that noise can be highly
irritating. Can it do something more than
irritate? Can it affect one's health?

3.4 Physiological Effects of Noise

Repeated exposure to high levels of noise will
result in hearing loss. The level of sound to
which residents or pedestrians are exposed
adjacent to a highway is not sufficiently great
to cause hearing impairment.

There is however some evidence that excessive
exposure to noise may be connected with hyper-
tension (26). The following statement is made
by the Health Commission in its submission (26):

"Noise is one of the stress factors
known to affect the immune system
so that animals housed in stressful
conditions (crowded and noisy) are
more prone to infection (Holt, 1978).
The situations in humans is not clear."

3.5 The Psychological Effects of Noise

The State Pollution Control Commission is charged
with the responsibility of investigating noise
complaints under the Noise Control Act, 1975.
In its Annual Report, 1978 it observed that noise
frequently aroused a degree of annoyance seldom
caused by other environmental intrusions. The
Report states (27):

"While there are no well-proven health
problems caused by noise, except hearing
loss in extreme cases, it is evident
that noise can cause stress, anxiety,
irritability, psychosomatic illnesses,
difficulty in sleeping and reduced
feeling of well being."

Annoyance itself, may, if it is persistent, affect
a person's health and well being (28). The

26. The literature is reviewed by the Health Commission
    in its submission to the Inquiry (S.K/C 342), page 12.
27. S.P.C.C. Annual Report, 1978 page 151.
28. Submission of the Health Commission (S.K/C 342),
    page 11.

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sensitivity, and vulnerability of individuals
to noise, and to stress induced by noise, will
obviously vary. There is the suggestion that
15-25% of the population is especially sensitive
to noise (29).

Support for the claim that noise does induce or
exacerbate psychosomatic illnesses, is to be
found in studies which examine community needs
for prescribed drugs before and after exposure
to noise. First, a study was made (Knipschild
and Oudshoorn, 1977) (30) of the prescriptions
filled by pharmacists in two villages in Holland
in the period 1967-1974. Before 1967 neither
area was affected by noise. After that date one
only of the villages was affected by noise
(occasioned by the opening of an airport). In
the village which was not affected, use of
sleeping pills and sedatives did not increase
over the period of the survey (1967-1974). In
the other village, where the residents were
exposed to noise, the consumption of sleeping
pills more than doubled by 1972. It then
reduced slightly. The reduction corresponded
with the introduction of a night curfew on
aircraft operations. A similar trend was found
with sedatives.

Closer to home, a similar study was carried out
by J.A. Wilson, a pharmacist in the inner Melbourne
suburb of Brunswick. He compared the number of
prescriptions for residents by 1976-1977 with those
in 1977-1978 after the opening of the F 19 freeway
which feeds into Brunswick. The a.m. peak flow of
vehicles on the particular street from which many
of his customers were drawn, was 2,230 cars per
hour on average. Between 6% and 9% of the traffic
flow consisted of trucks. Noise levels reached
75 dB(A).

29. "Roads and the Urban Environment”, O.E.C.D.,
    1974, page 171.
30. Quoted in the submission of the Health Commission,
    (S.K/C 342), page 11.

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The prescription statistics showed a 112%
increase in visits to the doctor. The prescrip-
tions for various ailments increased as follows:

TABLE 4.

BRUNSWICK PRESCRIPTION STUDY.

Prescriptions for bronchial
   ailments                         111%
For nerves                          263%
For sleep                           114%
For allergies                       240%
For headaches                        86%
For asthma                           83%
For nausea                          236%
For blood pressure                  105%
For nose                             15%
For eye                             170%
For ear                             120%

No doubt, to certain minds, the evidence of
physiological or psychological 'damage' through
noise falls short of scientific proof. The Inquiry,
for its part, endorses the conclusion of two
researchers, Ettema and Zielhuis, 1977, cited in
the submission of the Health Commission (31):

"We need not wait until full data is
available to join the noise abatement
movement. Noise is all around us
inducing many complaints and impair-
ment of well being, at least in its
psychological and social aspects..”

3.6 Interference with Social and Business Activities

Ordinary conversation is conducted at a level of
approximately 60 dB(A). If the level of noise
exceeds 70 dB(A) it will tend to interfere with
communication. It will make telephone conversations
extremely difficult, if not impossible. The
submissions are replete with examples of such

31. S.K/C 342 Health Commission, page 14.

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interference. Sound levels below 70 dB(A) may
interfere with ordinary household activities
such as listening to the radio, television or
recorded music.

Experiments show that work accuracy and quality
diminish in a noisy environment (32). That is
not to say that one should aim at the removal of
all noise. Curiously experiments also show that
a complete lack of noise results in human stress
and disorientation (33).

There is a suggestion that living in a noisy
environment may affect social interaction. The
following passage is taken from the Noise Impact
Assessment
submitted by the Planning and Environ-
ment Commission as part of its submission to this
Inquiry (34):

"In a pilot study of three residential
streets in San Francisco the effects
of different levels of traffic noise
on social behaviour were compared.
When traffic noise levels were high
little social interaction amongst
neighbours and a feeling of living in
a restricted environment were found.
The general level of satisfaction was
low and stress and withdrawal were
common among the residents. Those who
could move did so, leaving behind the
old and the poor (Day, 1975, page 12)."

It is evident that the community's concern about
noise is well founded. Each option must be
examined to judge the effect which it has upon
noise.


4. NOISE STANDARDS

4.1 Public Surveys

We have already said that noise is subjective.

32. NAASRA "Roads and Traffic Noise”, page 5.
33. SPCC Annual Report, 30th June, 1978, page 151.
34. PEC Noise Impact Assessment, page 12.


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One person's music is another's nightmare. Though
individuals differ in their response to specific
sounds, some broad generalisations can be made.
The generalisations are more likely to be true
in the case of traffic noise than in other areas
(such as music), because traffic noise meets with
universal condemnation from the community.

Surveys have been conducted to determine the level
at which people are annoyed by noise. In London a
survey was carried out between 1961 and 1963. It
concluded (35):

"From this survey it has been possible to
show that, taking all sites together and
median responses, people were as likely
to be satisfied as dissatisfied at the
L10 noise level of 70 dB(A) at external
facades when averaged over 18 hours of
the day from 6 a.m. to midnight."

A further study by Langdon (in the United Kingdom)
produced a somewhat lower figure. The survey
suggested that the point at which people begin to
become annoyed by noise (where dissatisfaction
begins to outweigh satisfaction) is around 66 dB(A)
for the L10 (i.e. intrusive noise) over the 18 hour
day between 6 a.m. to midnight (36).

The Land Compensation Act, 1973 (United Kingdom) and
the Noise Insulation Regulation, 1975, require compen-
sation in the form of insulation (and perhaps accompany-
ing ventilation) once noise levels exceed 68 dB(A)
measured one metre in front of the building facade.
A standard which more or less approximates the
results of the surveys, has, therefore, been
embodied in the legislation.

4.2 Different Standards for Different Land Uses

Whether noise is obtrusive, and therefore objection-
able, will depend upon the context in which it is
made. It is, perhaps, not helpful to speak of an

35. Report of Urban Motorways Project Team, page 32.
36. Referred to in Supplementary Paper No. 5 (Dr.
    Pearson-Kirk) Volume VI Enquiry into the N.S.W.
    Road Freight Industry Report.

-101-
'average noise level' without the context being
identified.

In the United Kingdom the matter has been examined
extensively by two committees. The first, The Wilson
Report
(37) assessed noise standards by the yardstick
that speech would suffer interference at 55 dB(A).
Standards were fixed according to maximum intrusive
noise (i.e. L10) inside the building. The standards
were (38):
  • Large conference and lecture
       rooms                            30 dB(A)

  • New school classrooms               45 dB(A)

  • Existing school classrooms          55 dB(A)

  • Private offices                  45-50 dB(A)

  • General offices                  55-60 dB(A)
The Wilson Report suggested the following internal
standards for an ordinary home:
  • 50 dB(A) in a busy urban area
  • 45 dB(A) elsewhere
  • 35 dB(A) in the metropolitan area at night
The Commission of Enquiry into the New South Wales
Road Freight Industry made the following statement (39):

"It has been widely accepted that noise
levels which should not be exceeded for
more than 10% of the time, should be:
Country areas      - daytime 40 dB(A)

Suburban areas     - daytime 45 dB(A)

Busy Urban areas   - daytime 50 dB(A)

The figures given (which are presumably internal
figures) are almost the same as those adopted by
the Wilson Committee.

37. Final Report of the Committee on the Problem
    of Noise, 1963.
38. Quoted page 35, Urban Motorways Project Team.
39. Commission of Enquiry into NSW Road Freight
    Industry Volume IV, pages 5/29-30.

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In 1971 the Noise Advisory Council reported in the
United Kingdom. The standard it adopted was less
stringent, and was an external standard i.e. measured
at the building facade. It said (40):

"We considered that it would be unreasonable
for future road schemes to be planned so as
to expose existing residents to noise levels
which a majority of them would be likely to
find unsatisfactory without some form of
remedy being available to them. We there-
fore recommend that in no circumstances
should existing residential development be
subjected, as an act of conscious public
policy, to L1O levels in excess of 70 dB(A)
unless some form of remedial or compensatory
action is taken by the responsible authority.
....We wish to stress however that an L10
level of 70 dB(A) constitutes in our view the
limit of the acceptable rather than the
standard which is desired. Wherever possible,
planners should design to lower levels."

It is not easy to compare the Wilson standard with
that of the Noise Advisory Council, since the former
is based upon internal noise, and the latter upon
external levels of noise. A comparison can be made
if one allows 10 dB(A) attenuation provided by the
building façade itself. That may be a generous
allowance in Sydney, where, more than likely, the
windows would be kept open.

The standards set by the Wilson Committee adjusted
to the external noise level, would therefore be as
follows:
Country areas      - daytime 5O dB(A)

Suburban areas     - daytime 55 dB(A)

Busy Urban areas   - daytime 60 dB(A)

In the United States of America, Curry & Anderson
(1972) (41) developed a range of noise levels,
which varied depending upon the nature of the land
use and the time of day.

40. Quoted Urban Motorways Project Team Report, page 36.
41. Quoted in the 5th A.T.R.F. Forum Papers published
    by the Australian Transport Research Forum, page 223.

-103-

TABLE 5.

ACCEPTABLE NOISE LEVELS FOR VARIOUS LAND USES.
(Curry & Anderson)



Land Use
RECOMMENDED MAX. SOUND PRESSURE
LEVEL L10-dB(A)

Time of day
At Property Line
Inside Structure
Residential:
Day
Night
70
65
65
55
Business, Commercial,
Industrial:

All

75

65
Education
Institutions

All

70

60
Hospitals
Rest Homes:
Day
Night
60
50
55
45
Public Parks
All
70
55


Source: Curry D.A. & Anderson D.G. (1972) “National
        Co-operative Highway Research Program Report
        No. 133, 1972.

The "standard” is of interest since a number of
schools and hospitals lie in close proximity to
various options.

In April, 1972 the United States Federal Highway
Administration published interim noise standards.
They relate to L10 (i.e. intrusive noise). They
specify the appropriate level for the particular
land use. The prescribed external limits are:
  • 60dB(A) for parks and open spaces where
            quietness is of primary importance.
  • 70dB(A) for residential areas.
  • 70dB(A) for schools, churches and hospitals.
  • 70dB(A) for recreation areas, playgrounds,
            active sports areas and parks.

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In addition to this external limit and interior
design noise level is specified. A level of
55 dB(A) is the appropriate internal design for
schools, hospitals, hotels, motels, etc. (42).

The Sydney Area Transportation Study adopted a
standard of 70 dB(A) (43). It did so on a number
of bases. First, it was the standard employed by
a number of overseas Road Authorities. California,
for instance, at that time, used a noise criterion
of 70 dB(A) L10 (i.e. intrusive noise exceeded for
10% of the time) as warranting noise control
measures. Secondly, according to their research,
70 dB(A) was found to be the maximum limit of noise
exposure in a residential area before the public
complained. Thirdly, a noise of approximately
70 dB(A) inhibits conversation. At that level it
is necessary to speak loudly to communicate over
a distance of two feet. It is necessary to shout
over a distance of eight feet. The standard
adopted was for the external facade of the
building.

4.3 Standards Association of Australia

The approach adopted by the Standards Association of
Australia is to contrast the intrusive noise with the
background noise. Adjustments are made to take
account of the particular character of the noise.
The 1973 standard (which preceded the present
standard, AS 1055 - 1978), contained the following
table:

42. “Effects of Traffic and Roads on the
    Environment in Urban Areas” O.E.C.D.
    1973, page 25.
43. S.A.T.S. Volume 3, Chapter X, page 15.


-105-

TABLE 6.

AUSTRALIAN STANDARDS ASSOCIATION.

Amount in dB(A)
by which Adjusted
Measured Noise
Level exceeds
the Acceptable
Noise Level





Public
Reaction



Expression of Public
Reactions in a
Residential Situation.

0-5


5-10


10-15




15-20



20-25



25 and over
Marginal


Little


Medium




Strong



Very
Strong


Extreme


From no observed reaction
to sporadic complaints

From sporadic complaints
to widespread complaints

From sporadic and wide-
spread complaints to
threats of community
action

From widespread complaints
to threats of community
action

From threats of community
action to vigorous
community action

Immediate direct community
and personal action


Source: AS 1055 - 1973, Appendix E.

The background noise can be either calculated by
reference to a table, or measured. The background
noise level, in effect, becomes the standard,
because intrusive noise is defined as noise which
exceeds that level by more than 5 dB(A).

5. NOISE MEASUREMENT

5.1 The Apparatus Used to Measure Noise

Complex and sophisticated noise measuring equipment
is available to measure noise levels. Elaborate
precautions are taken to ensure that the reading
obtained is not influenced by wind, rain or other
factors. It is not necessary to describe in detail
the method which is adopted beyond saying that
monitoring devices are capable of being left

-106-
unattended to measure noise levels over a long
period (i.e. a week). The peaks and troughs
are recorded, and the “intrusive noise” can be
distinguished from the “background noise”.

5.2 Measurement of Background Noise

It is sometimes not possible to measure background
noise either because of insufficient time or
inadequate equipment. One is simply confronted
by an intrusive noise which it is possible to
measure. In these circumstances the background
noise level can be calculated. The Australian
Standard 1055 - 1978 "Noise Assessment in
Residential Areas
" contains a table specifying
land use and the decibel readings for each. The
table is reproduced here:

TABLE 7.

CALCULATED BACKGROUND SOUND LEVELS FOR
DIFFERENT AREAS CONTAINING RESIDENCES



-107-


The standard has been influenced by International
Standards, and is said to have received general
acceptance by practising acousticians in Australia (44).
It is important that the standard be accurate.
 

It is the difference between background noise, as
measured, or calculated from this table, and the
foreground noise (the intrusive noise), which
determines whether or not the noise is "offensive”.
The S.P.C.C., which is charged with the statutory
responsibility of monitoring noise, makes the
following statement:

"In the simplest investigation only a decibel
measurement - in terms of dB(A) - of both
the noise source and the background noise is
made. An adjustment of up to 10 dB(A) is
then made to the measured noise level to
take account of the character of the noise.
If the adjusted noise level exceeds the
measured background noise level by more
than 5 dB(A), the annoying noise is deemed
to be 'offensive’". (45)

The S.P.C.C. undertook a study of certain categories
within the Australian Standard 1055 - 1978 to
confirm that the Standard was appropriate for
Sydney. The Commission found, however, that they
are "unrealistically high” (46). The average
measured background noise level in areas within
category R2 (areas with low density transportation)
were lower than the calculated value of 50 dB(A) by
an average of 10 dB(A) and a maximum of 17 dB(A).
They concluded:

"If a noise complaint had been received
from any of these sites and the back-
ground level had not been measured but
obtained from the standard, then the
complainant would be subjected to a
noise up to 22 dB(A) higher than would
normally be considered acceptable.
This finding represents a serious and
unacceptable discrepancy between measured
and calculated background noise level."

44. S.P.C.C. Annual Report 1978, page 160.
45. S.P.C.C. Annual Report 1978, page 158.
46. S.P.C.C. Annual Report 1978, page 162.

-107-

The 1978 Standard is itself a revision of a
standard published in 1973. Whether further
adjustments, appropriate for Sydney, are in
contemplation, is not stated.

6. NOISE PREDICTION

6.1 Noise Prediction Models

Mathematical formulae (called models) are
available to assist in the Prediction of noise
levels.

Now, there are a great many variables affecting
the intensity of noise and the way in which it is
dissipated or attenuated in the particular situa-
tion in which it is made. Dr. Pearson-Kirk in a
supplementary paper (No. 5) prepared for the
Commission of Enquiry into the New South Wales
Road Freight Industry
(47) recites variables
likely to affect the strength of the noise at
its source, as well as its "propogation". By
propogation is meant its passage as a sound wave
from its source to the surrounding area.
Paraphrasing those variables, they are:

(a)    variables which affect the strength
of the source of noise:
  • the number of vehicles on the road;
  • with respect to each individual vehicle:
- its speed
- the type of vehicle (and
especially whether car or
truck) and its condition
  • roadway factors:
- roadway grade
- roadway surface (and tyre tread)
- wet or dry surface
  •  driving conditions (e.g. free flow,
    acceleration etc.)

47. N.S.W. Road Freight Industry Second Report,
    Volume VI, Paragraph 6.1

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(b)    propogation variables
  • the distance from the sound source
  • the nature of the ground surface
    in between
  • the height of the noise emissions
    from vehicles
  • the height of propogation above
    ground surface
  • objects or structures which the
    sound may strike
  • weather conditions

In short, the nature and intensity of sound, at a
given point, is a matter of some complexity.

Models introduce simplifications in the hope that
they will not distort prediction. They pick and
choose between variables selecting those which
are felt to be the most important. A “factor”
designed to cover all remaining variables is
thrown into the mix. Obviously it would be almost
impossible to accurately predict each one of the
source and propogation factors (for instance
weather conditions).

6.2 The Burgess Model

A model or formula was developed overseas and
became known as the Delaney National Physical
Laboratory Equation. This equation was adjusted
by M.A. Burgess (University of New South Wales) (48).
The adjustment was designed to take account
of traffic conditions in the Sydney Metropolitan
Area, which were not free-flowing, and which involved
a good deal of stopping and starting. The Delaney
Equation was originally calibrated for free-flowing
traffic. The Burgess version simply omitted any
reference to speed.

The Burgess Model, therefore, had the great virtue
of simplicity. To predict noise one simply had to
know:

48. M. A. Burgess "Noise Prediction for Urban Traffic
    Conditions – related to Measurements in the Sydney
    Metropolitan Area – applied Acoustics Volume 10,
    No. 1, January 1977, pages 1 to 7.

-110-

  • the number of vehicles per hour
  • the percentage of heavy vehicles
  • the distance to the centre of the
    traffic flow on the nearside lane

6.3 Limitations of the Burgess Model

The two basic variables used in the Burgess Model
are traffic flow and the percentage of heavy
vehicles. Both these variables are themselves
predictions. They are the result of a separate
computer modelling process to which reference
has already been made. In so far as that process
suffers from defects, those defects must flow
through to the noise predictions.

The defects which may arise in traffic predictions
have already been discussed. Broadly they are of
two kinds: First, inaccuracies may exist in the
assumptions which underlie the modelling process, and
secondly, inaccuracies may arise in the mechanical
application of the modelling procedure.

Confining our focus on the latter, reference has
already been made to a number of "trip tables".
Trip tables are simply the end product of the
computer modelling process whereby the traffic on
each road (link) in the network (i.e. the
Metropolitan Area) is predicted. Each trip table
was developed because of inaccuracies discovered
in its predecessor. Four separate trip tables
(trip tables A, B, C and D) were developed and used.

The Planning and Environment Commission said in
evidence that (49) the traffic flows used for the
noise predictions were those derived from trip
table A. If this is right, those predictions were
superseded by three later trip tables. Doubts
must arise as to the accuracy (assuming all other
things to be accurate) of the findings.

49. Transcript 16th November, 1979, page 3.

-111-

Quite apart from these limitations, there are
certain limitations arising from the Burgess
Model itself. First, it was a model tested by
the Urban Transport Study Group in the course
of the Central Area Industrial Study (50). On
some roads the predicted noise level corresponded
very well with the measured noise level. On
other roads there was an unacceptable discrepancy.
In respect of Botany Road, the following is said (51):

"In theory, a noise model assumes that
the intensity of use of a particular
road is directly proportional to the
intensity of surrounding “land use".
For the Botany location this is not
true. The traffic volumes and
proportion of heavy vehicles are high
on Botany Road but the surrounding
area contributed little to the
background noise".

Secondly, the model quite deliberately omits speed
as a factor. In stop/start driving conditions the
noise is likely to be rather more than predicted
by the model.

Thirdly, concern was expressed by the Planning and
Environment Commission (52) about the ability of the
model to predict traffic noise where the percentage
of heavy vehicles rises above 18%. The comments by
Mrs. Burgess herself in a paper written jointly with
Associate Professor A.B. Lawrence for the Commission
of Enquiry into the New South Wales Road Freight
Industry
(53) are relevant.

The following is said:


50. U.T.S.G. Technical Appendix No. 2 “Noise Pollution”:
    Central Area Industrial Study, 1977, page 11.
51. ibid. page 12 (transcript).
52. Page 42, Transcript 16th November, 1979.
53. Supplementary Paper No. 6, Volume VI, page 2.

-112-
“However, the Burgess method.. was based
on traffic noise measurements made in
the Sydney Metropolitan Area and it has
not been validated for roads with low
traffic flows and very high percentages
of heavy commercial vehicles, which are
typical of many sites for which informa-
tion was supplied by the Commission."

Fourthly, the Model (again quite deliberately)
does not take into account topographical effects.
Certain topographical features in the area under
consideration are relevant to noise. There are
cliffs in Riverview Road, Earlwood. There are
certain features of the Wolli Creek Valley (54):

"As I live on one of the hills overlooking
the valley where this route would go
through, local knowledge of the area
prompts me to bring to your attention
what "experts" may be unaware of.
The valley is a natural amphitheatre.
From my place I can, very clearly and
distinctly, hear the children's voices
as they play in the creek, bush and
park. I assume it would also magnify
all traffic noises".

Fifthly, the Model (again quite deliberately)
measures the predicted noise at a particular
distance (9 metres) from the centre of the flow
of the nearside lane of the highway. It is said (55)
this is the "usual distance to the boundary
of a residential property in most of the study
area". There is no evidence before the Inquiry
that this is so. Indeed it is clear from
inspections made by the Inquiry that in many
cases this is not so. Some houses are closer than
the stated distance. The noise experienced by
these residents is likely to be greater than
that predicted. In other cases the reverse is
true. The average is by no means clear.

54. Ms. A.M. Colwill, S.K/C 346, page 3.
55. P.E.C., Noise Impact Assessment, page 16.

-113-
Yet despite these limitations, the Model performs
reasonably well. It has been used to predict
noise upon particular Sydney streets and the
prediction has been compared to a measurement
of the actual noise arising from traffic on that
street. In the absence of one of the limiting
factors (and there are others), the predicted
noise and the measured noise correspond rather
well.

In the Inquiry the problems occasioned by the
use of a superseded trip-table are a super-added
difficulty which must cause one to view with
caution the predictions which are made.

6.4 Other Noise Models

There are many other noise prediction models. In
the United Kingdom under the Noise Insulation
Regulations 1925, a person exposed to certain
levels of noise as a result of new or improved
roads is entitled to demand sound insulation.

Hence, for planning purposes, it has been necessary
to predict the number of persons affected. A model
has been developed averaging over 18 hours noise
levels which can be characterised as “intrusive”
(i.e. noise levels exceeded for 10% of the time
over 18 hours (L10 18 hours)). The complexity
of the model, and the number of factors which
must be known, can be gleaned from the succinct
description given by Dr. Pearson-Kirk (56):

"To predict the noise at the reception point,
the noise at 10 metres from the nearside
road edge is first predicted using the
traffic data, flow, speed and percentage of
heavy vehicles, allowing for the road
gradient and surface where appropriate.
A series of corrections to this 10 metre
noise level are then applied to allow for
propogation-distance of the reception point

56. Supplementary Paper No. 5, Volume VI, Commission
    of Inquiry into the New South Wales Road Freight
    Industry, paragraph 6.3.

-114-

from the road, nature of the intervening
ground and screening - and for
complexities such as non-uniformity of
the road, partial screening, angle of
view from the reception point, multiple
sources and reflection effects, all
appropriate to the particular situation."

6.5 Reservations Concerning Noise Modelling

Reservations were felt by this Inquiry concerning
noise modelling. The community's concern with the
problem of noise can scarcely be doubted. It was
evident to the Urban Transport Study Group when it
made its investigations (57). It was evident to
the Planning and Environment Commission when it
held public meetings and conducted surveys (58).
It was amply revealed by the submissions made to
this Inquiry.

To demonstrate that those charged with the
responsibility of assessing options share the
community's concern for noise, elaborate steps
are taken to construct intricate models to make
predictions of noise. That is not to say that
those predictions, when made, may not provide
insight into the noise which can be expected if
one were to select one option rather than another.
However, one may doubt the extent to which one is
really much better off than simply saying that
traffic is expected to increase by a certain amount,
or which a certain proportion will be heavy vehicles,
so that the noise environment will deteriorate to a
greater or lesser degree based upon one’s
experience with traffic flows.

The matter is raised because there are other less
dramatic and less elaborate ways in which those
responsible for assessing or promoting options can
demonstrate their concern for the "noise problem".
They are sometimes overlooked because all energy

57. C.I.A. Study, page 5, Chapter I.
58. P.E.C. "What You Said", Page 7.

-115-

is channelled into the elaborate and time-consuming
process of noise prediction. The other ways of
demonstrating that concern are dealt with in the
following section.

7. THE WAYS OF COMBATING NOISE

7.1 Introduction

It is possible to combat noise in a number of ways:-
  •  altering the traffic flow
  •  design features of the road
  •  alterations to land use
  • insulation of buildings adjacent
    to the road
  • the provision of barriers to
    intercept noise
  • attacking the noise at source by
    providing for quieter vehicles
In the Joint Study Report the noise objective is
stated in these terms (59):,

"minimize the impact of noise in
noise-sensitive areas."

In assessing whether this objective has been achieved,
the focus is almost exclusively upon traffic flow.
The elaborate noise prediction models are called in
aid. The other means are given less attention,
though they may be more effective.

7.2 Measures Dealing with Traffic Flow

That is not to say that traffic flow is unimportant
in the context of noise. Obviously it is important.
Its importance is diminished however, when one
appreciates the nature of the cure in the graph
which is reproduced on page 88 above. As stated by
NAASRA in its small publication “Roads and Traffic
Noise
" (60):

59. Joint Study Report, page 7.
60. "Roads and Traffic Noise”, NAASRA, page 4.

-116-
"The graphs show that noise levels
do not increase greatly when traffic
volumes exceed 1,000 vehicles per
hour”.

Unless the number of vehicles (and especially
the number of trucks) using the roads changes
fairly dramatically, the differences in noise
are not likely to be great, even though people
using the area may have the impression the
problem is growing (61).

Secondly, the noise environment in a particular
area can be changed by manipulating the traffic
flow in ways other than providing a new facility.
The introduction of a road hierarchy in which
residential streets are insulated from through
traffic may bring about a vast improvement in
noise levels. The Traffic Authority of New
South Wales in its publication ‘Guidelines for
Road Closures
' makes the following statement (62):

"A road closure can reduce or eliminate
noise in a local road, while the
displaced traffic may only slightly
increase (the) noise level in a
heavily trafficked arterial road
which already has a high noise level.
On the other hand a road closure, if
not properly planned, may signifi-
cantly increase annoyance on a road
with previously low noise levels.”

There is a third way in which the alteration of
vehicle flow can affect noise. The stop/start
traffic flow evident in a network which is
congested, is liable to increase noise. Measures
designed to eradicate congestion and bring about
free-flowing conditions will, therefore, reduce
noise to the extent to which such measures are
successful.

61. See Leitch ibid., page 111.
62. Traffic Authority of N.S.W. “Guidelines for
    Road Closures”, page 5.

-117-

If a new facility is likely to bring about changes
in the flow of traffic throughout portions of the
Metropolitan road system, it is crucial to examine
the areas in which those changes occur. Where the
traffic is attracted to the new facility, the
number of vehicles using certain roads will be
reduced. In other cases (typically access roads)
the number will increase. It is important to
know whether the traffic is subtracted from those
areas which are, by reason of the level of noise
presently experienced, areas already suffering a
noise problem. Should this not happen, then
obviously the new facility has failed in the
stated objective.

The flow of traffic may be altered so that areas
which did not previously suffer a noise problem
are suddenly exposed to high levels of traffic
and hence high levels of noise. The sudden nature
of that exposure (rather than the gradual build up
which occurs elsewhere throughout the Metropolitan
network) may itself be an aggravating factor.

7.3 The Highway Design

The design of a highway will affect the noise
experienced by residents living nearby. If the
level of the highway is beneath ground level
("in-cut") the noise will be less. Such roads
involve extensive earth-works, and are therefore
more expensive.

A road construction at ground level ("at-grade”)
is less expensive to construct. There is no
barrier (unlike the sides of a road in-cut) to
catch or deflect the sound of the traffic stream.
Accordingly, it is noisier.

Elevated roads are expensive to construct and can
be visually intrusive. They tend to spread their
noise rather more widely but generally less
intensely than other profiles. There are sections

-118-

in all options where either rivers or railways
must be crossed where the proposed highway will
be elevated. This will have an effect upon
noise in the surrounding area.

7.4 Alterations to Land Use

Land use planning is relevant to noise in a
number of ways. First, manipulation of land use
may alter traffic flows and thereby alter noise
levels. Professor W.R. Blunden makes the point
when he says (63):

"The policy goal in dealing with the
environmental impact of traffic should
be to reduce, as far as possible, the
disabilities created by poor land use/
transport systems...Certainly the
effects of noise, accidents, pollution
are in more or less direct proportion
to the amount of travel that needs to
be undertaken. If the land use plan
encourages more, rather than less and
requires a higher proportion to be by
car then the environment suffers
".
                     (emphasis added)

A policy directed towards reducing travel by
reducing the number of vehicles or vehicle
kilometres (by manipulation of land use) rather
than one which encourages traffic by meeting
every express or anticipated demand, may have a
corresponding effect in reducing noise. Certainly,
the option is worthy of examination. It appears to
have been largely ignored in the present Inquiry.
It is, by its nature, a long term strategy.

Secondly, having carefully plotted a suitable
road hierarchy, certain roads will be major
traffic arteries within that hierarchy. Efforts
should be made, by means of zoning and development
requirements, to ensure that the land use along
the major arteries is not sensitive to noise and
is "auto-oriented". By auto-oriented is meant
land use which provides off-street parking,
suitable means of access to the highway itself (to

63. Page 137, Chapter 8 "Transport Policy",
    Transport Policy in Australian Cities’,
    W.R. Blunden.

-119-
eliminate the practice, commonplace in Sydney,
of people backing the family car onto a major
road) and some insulation by the design and
placement of buildings which front the road.

On one view, unit development along a major
artery simply exposes a greater number of people
to traffic noise. If, on the other hand, high
density developments are carefully designed and
placed, so that the main facade provides some
insulation and is at a suitable distance from the
road (as with some high density dwellings along
the Pacific Highway on the North Shore of Sydney)
then, from the point of view of noise, and for
other reasons, one may be better off. Again, such
a strategy (whatever its detail) is, of necessity,
long term.

7.5 Insulation of Buildings

In the United Kingdom under the noise insulation
Regulation, 1975 the road builder is obliged to
specify all properties likely to be exposed to
levels of noise above a certain level, 68 dB(A) L10.
The owner of the property is able to require the
road builder to insulate the rooms of his dwelling
exposed to "excessive” noise levels. The insula-
tion may take the form of double glazing (i.e. two
window panes, with a pocket of air in between, which
are fixed in position and cannot be opened). In
some cases a double, or insulated door, may be
provided.

Insulation involves certain disadvantages. The
ordinary ventilation obtained through opening
windows and doors is lost. Alternative ventilation,
by means of an extractor fan or some other device,
may be necessary especially where combustion
appliances are used in the room.

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It is not surprising, therefore, to read the
conclusion of the Urban Motorways Project Team
in the United Kingdom (64):

“It must be remembered, too, that
objection to artificial ventilation
may match that to noise”.

In France, there is "a certain prejudice against
air conditioning”.(65) The provision of double
glazing with ventilation is therefore not often
an available option. Other ways have to be found.

Is such a measure appropriate in Australia? The
Report of the Committee of Inquiry into Town
Planning Compensation presented to the Premier
of Victoria in March, 1978 suggested that it was (66).

What is appropriate for Melbourne, with its climate,
is not necessarily satisfactory for Sydney. The
S.P.C.C., in another context (67) suggest that "in
the Australian climate, windows have to remain
open for a substantial part of the year" so that
insulation by double glazing and ventilation may
not be an available option. Perhaps it should be
left to the individual. He or she should be given
the benefit of insulation and air-conditioning or
a lump sum equivalent.

Where it is thought appropriate to provide insulation
or compensation, the cost is included in the cost of
the highway. It therefore affects cost/benefit
analysis (68).

64. The Report of the Urban Motorways Project Team
    to the Urban Motorways Committee 1973, page 40.
65. "Roads in the Urban Environment" O.E.C.D., page 71.
66. Supplementary Paper 5 by Dr. Pearson-Kirk,
    paragraph 8.4 in the Supplementary Papers
    Volume VI, Commission of Inquiry into the
    N.S.W. Road Freight Industry.
67. Page 5, S.P.C.C. Submission S.K/C 339.
68. Leitch Committee Report, page 84.

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7.6 The Provision of Barriers or Earth Berms

The further alternative is to establish a barrier
adjacent to the highway to intercept and deflect
sound (to create an acoustic shadow). The
barriers must be continuous unless pockets of
high noise can be accepted. They need not be
massive (69). Effective barriers can reduce
noise by up to 25 dB(A) . Reductions of 10 dB(A)
will in practice be more common (69). It will be
remembered that a reduction of 10 dB(A) is the
equivalent of halving the relative loudness.

The Planning and Environment Commission in its
submission (70) provided a diagram depicting five
alternative designs. The diagram is reproduced
here. (Figure 10). A full earth berm is 18 metres
wide and at least 3 metres high. Its construction
is expensive. The land necessary for its construc-
tion is extensive (and also expensive). The cure
may be worse than the disease. The social
dislocation occasioned by resuming more land for
the berm is likely to be greater than suffering
the noise.

A wall can be provided where the land ‘take’ is
no more than 2.4 metres. Again there is a cost
in economic and social terms. The erection of a
3 metre wall, even where it is softened by
foliage, may be more offensive to some than the
noise from traffic using the highway. With the
Cooks River option, where such a wall may block
views of the river, this may especially be the
case. The subject will be further examined in
the commentary upon each option.
Where the road is elevated the observation of the
Urban Motorways Project Team (71), is of interest:

69. Report of the Urban Motorways Project Team to
    the Urban Motorways Committee, page 40.
70. P.E.C. Submission S.K/C 947.
71. Urban Motorways Project Team, page 157.

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FIGURE 10.




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"For a fully elevated road, the choice
of solutions to meet external noise
and visual intrusion "standards"
hinges on the selection of a barrier.
In the terms of this analysis a low
barrier 1.5 metres high generates
very little more visual intrusion
than a road without a barrier, and
can achieve a significant improvement
in the noise climate...”

An assessment must be made of the likely spread
of the noise, and its intensity by the time it
reaches the residences below. Noise contours
can be calculated. They must be calculated when
making an assessment of the appropriate design.

There is no doubt the drivers enjoy good views
from an elevated structure such as the Gladesville
Bridge or the recently constructed Bondi by-pass.
If this can be achieved without subjecting nearby
residences to unreasonable noise, so much the
better. If, however, the intensity and spread of
the noise is unacceptable, consideration to a
barrier should be given.

7.7 Insulation of Motor Vehicles

What legislation presently exists prescribing
noise levels? What scope is there for demanding
more stringent standards?

The legislative framework is complex. Under
regulation 106(1) of the regulations made under
the Motor Traffic Act, 1909, as amended, it is
an offence to drive a motor vehicle which causes
"any undue noise". Vehicles which fail to meet
an acceptable standard (whatever that may mean)
may be given a defect notice. They should not
pass the mechanical test required for annual
registration.

For some time, however, the need had been felt for a
more objective standard. Regulations made under
the Noise Control Act, 1975 (operating from 1st

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July, 1979) prescribe maximum noise levels for
motor cars and motor cycles. The levels are:
  • 96 dB(A) for motor cars
  • 100 dB(A) for motor cycles
The measurement is made 0.5 metres from the exhaust
outlet under specified operating conditions.

Regulations are being introduced which will have
application to commercial vehicles and which will
prescribe a range of noise levels for various
types of vehicle.

Quite apart from these provisions, there are
provisions which apply to newly manufactured motor
vehicles. The standards are embodied in the
Australian Design Rule No. 28 and No. 28(A)
respectively.

There are two critical matters in respect of any
standard:
  • the first is the decibel level
    prescribed
  • the second is the test procedure
    specified
The original design rule, Australian Design Rule
No. 28, attracted widespread criticism. The
criticism was directed at both the standard
specified and the test procedure (72). It was
regarded by many as simply embodying the status
quo
without affecting any worthwhile improvement.
A new design rule was drafted and endorsed by
the Australian Transport Advisory Council in
February, 1976. The prescribed standard was
more stringent. The test procedure still
remained "less than satisfactory" (73) Pressure

72. Supplementary Paper No. 5, Volume IV, N.S.W.
    Road Freight Inquiry, paragraph 5.1
73. Volume IV, N.S.W. Road Freight Industry Report
    page 5/30.
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was brought to bear by motor vehicle manufacturers
and its implementation was deferred. It is
expected to apply from 1st Ju1y, 1990. The
standards can be appreciated from the following
table.

TABLE 8.

AUSTRALIAN DESIGN RULES.


Vehicles first manufactured
on or after



1.7 .75



1.7.80

up to 3.5 tonnes

= 85dB

82dB

over 3.5 tonnes but not exceeding
12 tonnes
= 89dB

87dB

over 12 tonnes with
engine output up to 150kw
= 89dB

87dB

over 12 tonnes with
engine output exceeding 150kw
= 92dB

89dB



7.8 Encouragement of High Occupancy Vehicles

Elsewhere in this Report, consideration has been
given to policies directed towards the encouragement of
high occupancy vehicles. If traffic demand can be
accommodated by this means rather than building new
facilities, some sections of the community at least
will be spared the noise which inevitably accompanies
the provision of a new road.

7.9 Encouragement of Other Transport Modes

It has been said elsewhere in this exposition on
noise that the number of vehicles, and especially
the proportion of heavy vehicles, are the important
determinants of traffic noise. Consideration
should, therefore, be given to policies which may
encourage a net reduction in either motor vehicles
or trucks. Such a reduction is likely to improve
community noise levels. Policies directed towards
encouraging commuters to use their vehicles less for

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the journey to work or to use them for only part
of that journey may bring about a corresponding
improvement in noise levels throughout the
network. ”Park-and-ride” facilities, where a
parking station is provided at a railway station,
is a good example of a policy which is not
specifically directed to noise but which may
yield benefits in that area.

The problem posed by the number of trucks within
the Metropolitan Area is perhaps more difficult.
All but a tiny proportion of goods carried within
the Metropolitan network are carried by truck (74).
There is less scope for reducing the number of
trucks. This Inquiry, however, has before it a
number of specific proposals directed towards the
encouragement of containers to be transported by
rail for at least part of their journey. That is
a complex matter which is separately considered (75).
Insofar as containers can be diverted from road
vehicles to rail, the community may be spared,
and noise levels may be lowered.

74. Rimmer “Urban Goods Movement”, Commonwealth
    Bureau of Roads (March, 1976, page 5.
75. Volume I Containers, October, 1980.