Effects of road traffic noise on a residential community

Publisher’s version / Version de l'éditeur:

Vous avez des questions? Nous pouvons vous aider. Pour communiquer directement avec un auteur, consultez la première page de la revue dans laquelle son article a été publié afin de trouver ses coordonnées. Si vous n’arrivez pas à les repérer, communiquez avec nous à PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca.

Questions? Contact the NRC Publications Archive team at

PublicationsArchive-ArchivesPublications@nrc-cnrc.gc.ca. If you wish to email the authors directly, please see the first page of the publication for their contact information.

https://publications-cnrc.canada.ca/fra/droits

L’accès à ce site Web et l’utilisation de son contenu sont assujettis aux conditions présentées dans le site LISEZ CES CONDITIONS ATTENTIVEMENT AVANT D’UTILISER CE SITE WEB.

Building Research Note, 1977-02

READ THESE TERMS AND CONDITIONS CAREFULLY BEFORE USING THIS WEBSITE. https://nrc-publications.canada.ca/eng/copyright

NRC Publications Archive Record / Notice des Archives des publications du CNRC :

https://nrc-publications.canada.ca/eng/view/object/?id=cc12632a-a778-45e1-91c2-aac8ab27e5f0 https://publications-cnrc.canada.ca/fra/voir/objet/?id=cc12632a-a778-45e1-91c2-aac8ab27e5f0

NRC Publications Archive

Archives des publications du CNRC

This publication could be one of several versions: author’s original, accepted manuscript or the publisher’s version. / La version de cette publication peut être l’une des suivantes : la version prépublication de l’auteur, la version acceptée du manuscrit ou la version de l’éditeur.

For the publisher’s version, please access the DOI link below./ Pour consulter la version de l’éditeur, utilisez le lien DOI ci-dessous.

https://doi.org/10.4224/40000592

Access and use of this website and the material on it are subject to the Terms and Conditions set forth at

Effects of road traffic noise on a residential community

EFFECTS OF

ROAD

TRAFFIC

NOISE

ON

A RESIDENTIAL COMWWI"Y

by

J.D.

Q u i r t

1. INTRODUCTION

In A u g u s t 1976, as part of a c o n t i n u i n g study of the effects o f road and rail n o i s e an residential areas, a study of the n o i s e environment in the South Keys area of O t t a w a was undertaken.

This area was chosen because of proposed changes

i n

the road system which could be expected to produce changes in t h e noise pattern. This r e p o r t , the "befo~e'' p o r t i o n of the study, i n c l u d e s a survey o f e x i s t i n g noise and a p r e d i c t i o n of f u t u r e n o i s e l e v e l s .

A n effort is made to r e l a t e these noise levels to widely accepted n o i s e criteria, in o r d e r to provide a basis for e v a l u a t i o n of t h e

environmental impact o f t h e proposed development.

This r e p o r t is subdivided i n t o four sections. Section 2

introduces same of the relevant units for describing n o i s e and some proposed standards f o r noise limits to get he^ w i t h brief

indications o f t h e i r implications, A description o f t h e equipment and procedures used in the noise survey and a swmnary of the

results are contained in the Section 3 . Section 4 contains some

predictions o f the changes in n o i s e levels associated w i t h changes

in road use, and d i r e c t l y relates t h e s e t o the c r i t e r i a discussed in Section 2.

2 . ENVIRONMENTAL NOTSE DESCRIPTION AND CRITERIA 2 - 1 Noise Units

A b r i e f , very superficial description of t h e relevant units will be presented. More technical details and e x p l a n a t i o n s may be found in t h e listed ~efesences,

S t u d i e s of environmental n o i s e and t h e

associated

community response normally use the A-weighted sound l e v e l as the b a s i c

measure of n o i s e intensity. The A-weighting causes t h e measure-

ment system to respond to high- and low-pitched sounds i n

approximately the same way as does t h e human ear in judging

loudness. More directly, A-weighted levels are found to correlate well with human assessment of the noisiness or annoyance

associated with intrusive sounds.

The n o i s e emitted by road t r a f f i c f l u c t u a t e s with p a s s i n g time, b o t h qn t h e s h o r t time

scale

( a s i n d i v i d u a l vehicles p a s s by] and on the longer scale (as

f o r

example i f t r a f f i c volumes

are smaller at night). In order to d e s c r i b e such noise, a

measure called the "equivalent sound level" is commonly used. T h i s is t h e l e v e l of a steady sound carrying the same energy

as the time-varying sound during the s p e c i f i e d t i m e p e r i o d . When assessing the environmental impact of t r a f f i c noise it is common t o c o n s i d e r dayrime a n d nighttime p e r i o d s separately. For

purposes o f this r e p o r t t h e Daytime Sound Level (Ld) is the A-weighted equivalent sound l e v e l f o r t h e time period from 0700 t o 2300 hours; the Nighttime Sound Level

[h)

is t h e A-weighted e q u i v a l e n t sound level from 2500 to 01700 hours.

Although b o t h Ld and are of i n t e r e s t is assessing a noise climate, it is generally considered more convenient to have a sZLnglc noise index to characterize a site. The Day-Night Average Sound Level (Ld,) developed by the U . S . Environmental Protection Agency is the A-weighted equivalent sound l e v e l for a 24-hour time period w i t h a 1 0 dB c o r r e c t i o n added t o the

actual sound l e v e l during the n i g h t t i m e hours. This correction to the n i g h t t i m e level is justified by the increased sensitivity

to n o i s e at night when most people are s l e e p i n g (or t r y i n g to sleep). The n i g h t t i m e p e r i o d used for the exact d e f i n i t i o n of Ld, is from 2200 t o 0700 hours. For purposes of this report, however, the values f o r the n i g h t and day periods indicated in t h e d e f i n i t i o n s o f Ld and

L,,

will be used to obtain an

approximate Ldn. The difference is negligible

in

most c a s e s , and x h i s permits comparison with the standards proposed by the

Ontario Ministry

of

t h e Environment.

2.2 Typical Community Response

I n order t o make use of n o i s e survey, one must establish the r e l a t i o n s l l i p between n o i s e levels and human reaction t o such noise levels. In recent years many large surveys have been made both in North America and in Europe to determine the typical. community reaction to intruding noise. An excellent

summary of t h e results of t h e s e studies has been published

('1.

Figure la, which was taken from ( 1 1 , shows t h e data f a r

one

group of 55 communities which were studied. It is c l e a r from t h e Figure t h a t there

is

considerable variation in cornunity

response and that p r e d i c t i o n of t h i s response simply on the b a s i s o f

Ld,

is not very r e l i a b l e . The mean valve of outdoor

Ldn associated with "no reaction1" is 55 dB; with f ' v i g a ~ o u s

Much more reliable p r e d i c t i o n o f cormunity response i s

possible u s i n g t h e "Normalized Day-Night Level" which is

obtained by adding t o Ld, several corrections associated w i t h t h e nature o f t h e n o i s e and the community. These corrections

a r e listed in Table I , and Figure l b shows how t h e use of t h e s e

c o r r e c r i o n s reduces t h e scatter in the community response. It appears that the normalized outdoor Ld, provides a reasonably

accurate assessment of the impact of an intruding noise on a

community.

Some Recommended Environmental Noise Criteria

A t this t i m e very l i t t l e legislation t o protect the public f r o m noise has been enacted. Recommendations f o r appropriate nois'e criteria have been proposed, however, by v a r i o u s government agencies, b o t h in Canada and in the U . S . A .

Probably the most far reaching s t u d y of n o i s e problems has been made by the U . S . Environmental Protection Agency. It

i d e n t i f i e d an outdoor Ld, o f 55 dB and an indoor Ld, of 45 dB a s

thc maximum levels consistent with "protecting p u b l ~ c health and welfare with an adequate margin o f safety." An extensive

discussion of t h e r e a s o n s f o r t h i s recommendation is given in

Ref. (1). Note t h a t an outdoor nonnalised Ld, of 55 dB corresponds to t h e community reaction category "no r e a c t i o n , although n o i s e i s generally noticeable."

Within Ontario, essentially similar n o i s e level limits for r e s i d e n t i a l areas are recommended by the Ontario Ministry of t h e Environment. In t h e Model Municipal Noise Control By-Law ( 2 ) the sound l e v e l l i m i t s s p e c i f i e d a r e Ld o f 55 d B for outdoor recreation areas (45 dl3 for i n s i d e the house] and of SQ dB for outdoors (40 dB far indoor space intended for sleeping].

These values f o r Ld and

L,

correspond to an outdoor Q, limir

af approximately 57 dB. The M i n i s t r y of t h e Environment recommends that new housing developments conform to t h e s e limits, although

levels 5 dB h i g h e r are considered acceptable in cases where

a d d i t i o n a l homes are being constructed in an e x i s t i n g community.

3 . NOISE SURVEY IN SOUTH KEYS

Outdoor n o i s e measurements were made for one or more days a t each of several s i t e s in t h e South Keys area during the p e r i o d from 13 September to 8 O c t o b e r 1976. The n o i s e was measured u s i n g a Metrosonics dB602 sound level analyzer and a Bruel

E

Kjaer Type 4145 microphone with Type 2619 preamplifier and Type UA0207 windscreen. Data were read out from the a n a l y z c ~ a f t e r

to t h e Fietrosonics a n a l y z e r . The system calibration was checked

before and a f t e r each measurement p e r i o d , using a Bruel E Kjaer Type 4230 pistonphone. This equipment is almost completely automatic; the r o u t i n e o p e r a t i o n s to obtain t h e d a i l y p r i n t o u t of data were performed by householders

in

t h e South Keys area.

Tlle measurement s i t e s were cIaosen t o provide a r e p r e s e n t a t i v e

crass-section of t h e n o i s e environment

i n

t h e v a r i o u s p a r t s o f t h e c o m i t y . The locations of tlre sites are shown in Figure 2 and a d e r a i l e d d e s c r i p t i o n of t h e microphone locations is given in Table IT. S i t e s 5 and 4 were chosen to i n d i c a t e typical n o i s e l e v e l s near t h e middle of the community where t r a f f i c noise i s m i n i m a l . The other s i t e s were exposed to t h e n o i s e fxom t h e more heavily-used r o a d s around the p e r i p h e r y of the community.

The data from these measurements a r e shown in Figures 3a to

3f, and are summarized in Table TIT. Because the measurement system responds spuriously to r a i n o r high winds, data from

periods when such weather c o n d i t i o n s might have distorted t h e results were d i s c a r d e d .

Scvcral f e a t u r e s of the data obtained are noteworthy. With

t h e exception of some of t h e d a t a in F i g u r e 3a, t h e sound levels shown in FiLgures 3a to 3f are the average equivalent sound

pressure l e v e l s o v e r four-hour p e r i o d s . It can be seen fxom Figure 3a t h a t while the use of s h o r t e r {one-hour) averaging p e r i o d s shows more clearly the variations in noise level on t h a t particular day, it a l s o obscures t h e over-all t r e n d s in

the data.

Several trends are e v i d e n t . A t a l l s i t e s the n o i s e level was s i g n i f i c a n t l y lower during the nighttime p e r i o d (2300 h r t o 0700 h r ) than during the daytime. Secondly, t h e noise l e v e l s at sites near the middle o f the conununity were generally lower than t h e levels at s i t e s exposed t o n o i s e from t h e major t r a f f i c

r o u t e s .

Traffic i s not t h e only source of noise in the community, however. Particularly h i g h n o i s e l e v e l s were observed i n the period f ~ o m 1500 to 1900 hours on 23 September (at S i t e 3) and from 1900 to 2300 hours on 26 September (at S i t e 5 ) . These have

been attributed to t h e low altitude flypast of a i r c r a f t going to

ox from t h e nearby airport. S i m i l a r results might be o b t a i n e d if a neighbour" lawn was cut using a power mower. Table LII

contains calculated values of Ld,

b,

and Ld, f o ~ S i t e s 3 and 5 , both with these unusually noisy periods included i n t h e a v e r a g i n g

and with those periods excluded. The l a t t e r values are more suitable

f o r

estimating t h e noise reaching t h e s e sites

from

t r a f f i c on the nearby roads.

The normalized Ld, values in Table 111 w e s e obtained using appropriate corrections from Table I . Because t r a f f i c noise

c o n t a i n s

no

pure tones and is present throughout t h e year, and because it is usually considered t h a t some effort is made to control t h e noise, corrections of 0 dB were used except in the

category f o r type o f community. Although S i t e s 3 , 4 and 5 would qualify as "urban residential," t h e o t h e r three s i t e s are c l e a r l y "adjacent to h e a v i l y travelled roads and industrial aseas.lt Therefore 5 dB was subtracted from t h e measured Ldn

l e v e l s a t Sites 1, 2 and 6 t o o b t a i n t h e normalized Ld,. With ~ h e s e c o r r e c t i o n s , only Site 6 has noise l e v e l s outside the r a n g e f o r which the expected community a t t i t u d e is "no r e a c t i o n although n o i s e is generally noticeable.'' Although the n o i s e Eevels at S i t e s 1 , 2 and 5 are s l i g h t l y above t h e limits recommended by t h e O n t a r i o Ministry o f t h e Environment, they are sufficiently c l o ~ e

to those Eevels that one would p r e d i c t only marginal interfcrencc with such activities as sleep and speech communication.

Note that although Site G would not be suitable f o r normal

i-esidential development, it is an acceptable s i t e f o r a motel

where outdoor r e c r e a r i o n space is of l i t t l e importance and

adequate sound irlsulation can be provided to ensure negligible

s l e e p disturbance.

4 . ANTICIPATED CHANGES IN THE NOISE ENVIRONMENT

As part of t h e development of the South Ottawa Eastern Community, it is proposed t h a t Johnston Road and Hunt Club Road

s h o u l d be extended eastwards to Conroy Road and Hawthorne Road. These changes i n t h e road system w m l d result in substantially

increased traffic en J o h n s t o n Road and Hunt Club Road. The primary purpose of t h i s s e c t i o n of this r e p o r t is t o estimate t h e resulting changes

in

the noise climate in South Keys and to r e l a t e the anticipated noise levels t o t h e social response

c r i t e r i a presented in Section 2 . 4 . 2 P r e d i c t i o n of Road T r a f f i c Noise

Various research groups have developed formulae for calcu-

lating the equivalent sound l e v e l s produced by road traffic. Although the various models d i f f e r in some details, they a l l

give fairly similar results and

are

typically accurate to w i t h i n 2 dB. The calculations presented here use t h e p r e d i c t i o n method developed by t h e Ontario Ministry of Transportation and

Communications

13).

The A-weighted equivalent noise l e v e l may

be calculated u s i n g t h e following equation:

Leq = 49.5 + 10.2 loglD (V, + 6Vt) - 1 3 . 9 loglO(D) + 0.21 S

where :

=es

= t h e A-weighted e q u i v a l e n t sound level _{one-hour period} (in dB) f o r a V, = number of cars per hour (Gross Vehicle Weight under

Vt = number of trucks per hour [Gross V e h i c l e Weight o v e r 10,000 l b )

D

= d i s t a n c e t o t h e edge o f t h e pavement (in ft] S = average t r a f f i c speed (in mph).

T h i s e q u a t i o n predicts the n o i s e l e v e l in the absence o f any buildings, or o t h e r s u r f a c e s , from which sounct might be r e f l e c t e d .

Far comparison with t h e results reported in Section 3 , an additional correction must be made f o r r e f l e c t i o n s from the houses.

4 . 3 Predicted N o i s e Levels at S i t e 5

A t S i t e 5 [on Southgate Road at the southern extremity of South Keys), t h e traffic

on

t h e proposed extension of Hunt Club

Road is t h e p o t e n t i a l noise scurce o f i n t e r e s t . The worst-case peak-hour r r a f f i c volumc anticipated on t h i s road

c4)

is 2450

vehiclesJhour with 7 p e r cent heavy vehicles. The estimated hourly average f o r a 12-hour day (presumably 0700 to 1900 h r ) i s obtained by multiplying the peak-hour v a l u e by 10/12. Thus f o r t h e daytime p e r i o d on t h i s road t h e following v a l u e s a r e a p p r o p r i a t e :

Several possible alignments of Hunt Club Road have been d i s c u s s e d . The d i s t a n c e (D) from the edge of t h e pavement to t h e

homes on Southgate Road obviously depends on the alignment s e l e c t e d , but s h o u l d not in any case b e l e s s than 200 ft. Using D = 2 0 0 ft

and t h e values f o r Vc, Vt and 5 i n d i c a t e d above, t h e equation gives an average n o i s e level f o r t h e daytime period o f 58.9 dB. F o r purposes o f comparison with t h e existing s i t u a t i o n [as shown by

the results reported in Section 3 2 , it i s necessary to add 3 dB

t o t h i s value t o allaw for the noise reflected f ~ o m the houses. l l u s t h e average noise l e v e l in the f r o n t yard during t h e daytime

p e r i o d i s predicted to be 62 dB. The average n o i s e levels

in t h e

evening period [1900 to 2300 hr] would t y p i c a l l y be lower than

the average daytime level by approximately 5 dB and t h e nighttime n o i s e l e v e l s (2300 hr to 0700 h r ) would be approximately 8 dB

lower t h a n t h e daytime l e v e l s . These differences are a d m i t t e d l y approximate, but are c o n s i s t e n t both w i t h "typical" noise survey results and w i t h t h e iesults given in Section 3 for t h e s i t e s

exposed t o t h e n o i s e from nearby heavlly-used roads.

Using these values, t h e Day-Night Average Sound Level

(Ld,l

T h i s n o i s e l e v e l exceeds t h e limits recommended by r h e U . S .

Environmental P r o t e c t i o n Agency and the O n t a ~ i o B I i n i s t r y of t h e Environment by 7 dB and 5 dB, respectively. In addition, it is 5 dB h i g h e r than the noise levels attributed To road traffic undcr e x i s t i n g c o n d i t i o n s (as presented i n Section 3 3 , This

d i f f e r e n c e i s marginally noticeable, b u t it i s nevertheless unlikely t h a t the response o f residents on Southgate Drive will exceed t h e "sporadic complaintsT' category of F i ~ r e l b .

4 . 4 Predicted Noise Levels at S i t e 1

A t Site 2 [and a l l the other homes an t h e n o r t h s i d e of Eernwood Drive and Viking Drive) t h e traffic expected on Johnston

Road, i f i t is extended to Conroy Road, is t h e most serious

p o t e n t i a l noise source. The e s t i m a t e d worst-case peak-hour t r a f f i c volume predicted f o r this road

141

is 1590 vehicleslhour with

5 p e r cent heavy vehicles. The approximate average traffic

density for a 12-hour daily period may then be c a l c u l a t e d to be:

V, = 1260 carsjhour

Vt = 65 heavy vehiclesJhour

The proposed speed limit f o r Johnston Road is S = 30 mph and t h e distance from the edge of the pavement to the p o i n t where

the microphone was located at Site 1 is 40

f r

allowing f o r a

pavement width of 1 5 ftllane. Using t h e s e values in t h e equation,

and adding 3 dB f o r t h e noise reflected from t h e wall of the house,

gives a p r e d i c t e d average n o i s e level at Site 1 of 6 9 - 3 dB f o r

the daytime period COT00 to 1900 hour]. As in t h e analysis for

Southgate Road, allowing f o r reduced noise during t h e evening and n i g h t t i m e periods leads t o predicted noise levels of 64 dB for

t h e period from 1900 to 23QO hr and 6 1 dB f o r t h e period from 2300 t o 0700 h r . Combining these predictions, the Day-Night

Average Sound Level (Ldn) was calculated to b e :

Lam = 70 dB

This substantially exceeds t h e 57 dB limit recommended by the Ontario M i n i s t r y of the Environment and the 55 dB level i d e n t i f i e d by t h e U . S . Environmental Protection Agency as "requisite to

protect p u b l i c health and welfare with

an

adequate rhargin of safety." Although this l e v e l should be typical in t h e part of t h e yard near t h e wall of t h e house, sohewhat higher levels would b e expected closer to Johnston Road,

In assessing t h e impact of this n o i s e , one should recognize t h a t the areas most severely affected are the backyards o f t h e

homes, ~lrhich have been used as o u t d o o r r e c r e a t i o n areas f o r s e v e r a l years. I n d o o r levels, however, will a l s o he a f f e c t e d , particularly d u r i n g the summer when it is necessary to open t h e wind or*.^ f o r ventilatj on.

AT d i s c u s s e d in Section 3 , t h e Normalized Outdoor Ld, may

be o b t a i n e d by s u b t r a c t i n g 5 dB from t h e measured value of Ld,.

As shown by t h e graph i n Cigure l h , typical community response when exposed to such n o i s e would include widespread complaints and p o s s i b l e threats o f l e g a l a c t i o n .

ht the second row of housing f r o m Jolmston Road [on t h e s o u t h s i d e o f Fernwood D ~ i v e and Viking Drive] the a d d i t i o n a l d i s t a n c e from t h e noise source and the protection provided by t h e

i n t e r v e n i n g row of houses should he s u f f i c i e n t to reduce t h e n o i s e t o acceptable l e v e l s .

The existing n o i s e l e v e l s in the South Keys community are t y p i c a l of a residential urban a r e a . Alrhough t h e n o i s e l e v e l s at homes around t h e p e r i p h e r y o f the community ( a d j a c e n t to more heavily-used r o a d s ) are s l i g h t l y above the limits proposed by

govemmcnt agenctcs such as the Ontario Ministry of the Environment, the e x i s t i n g n o i s e problem does not seem s e r i o u s .

The proposed extension o f FIunt Club Road and Johnston Road will significantly increase t r a f f i c passing t h e southern and n o r t h e r n edges of South Keys. Although the resulting increase

in n o i s e l e v e l s will be n o t i c e a b l e a t homes on Southgate Drive ar the southern edge o f t h e community, it s h o u l d n o t seriously

i n t e r f e r e with normal a c t i v i t i e s . The increased n o i s e levels at homes adjacent t o Johnston Road, however, w i l l c o n s t i t u t e a

s e r i o u s n o i s e problem.

ACKNOWLEDGEMENTS

The author w i s h e s to thank the Eastern Community Citizens

P l a n n i n g Committee for their h e l p in arranging f o r r e s i d e n ~ s of S o u t h Keys t o place t h e noise m o n i t o r on their p r o p e r t y and o b t a i n t h e d a t a p r i n t o u t s , Thanks are also due to Mr. Ken Goselin of

the T r a n s p o r t a t i 0 ~ 1 Department o f the Regional Municipality of

Ottawa-Carleton for supplying d a t a on t h e a n t i c i p a t e d changes i n t r a f f i c volume.

REFERENCES

1. I n f o m a t i o n on Levels of Environmental Noise Requisite t o P r o t e c t P u b l i c Health and Welfare with an Adequate Margin of Safety. U.S. Environmental P r o t e c t i o n Agency Report

550/9-74-004 (March 1 9 7 4 ) . Available from S u p e r i n t e n d e n t of Documents, U.S. Government h i n t i n g Office, Washington,

DC 204112.

2 . Model Municipal Noise C o n t r o l B y - L a w . O n t a ~ i o Ministry o f t h e

Environment (May 1976)

.

Avail a b l e from Ministry o f Government Sexvices P u b l i c a t i o n C e n t r e , Macdonald Block, Toronto, Ontario, M7A 1W8.

3 . Hajek, J . J . Ontario Leq P r e d i c t i o n Method: A Brief Outline. Systems Research and Development Branch, O n t a r i o Ministry of

Transportation and Communications (June 1976).

4 . Predicted t r a f f i c volumes. Obtained from Mr. Ken Goselin, T r a n s p o r t a t i o n Department, Regional Municipality of Ottawa- Garlet en.

TABLE I Type o f Correction Seasonal Correction Correction f o r QUtdoor

Noise Level

Measured in Absence o f I n t r u d i n g Noise C o r r e c t i o n s to be added t o t h e o u t d o o r Day-Night Sound Level (Ldn) of i n t m d i n g n o i s e to obtain

t h e normalized La, (from R e f . 1)

Summer (or year-xound operation)

Winter only ( o r windows always closed]

Amount of Correction to b e Added to Measured La, in dB Y Quiet suburban or r u r a l community Cremate from l a r g e + 10 c i t i e s and from industrial activity and t r u c k i n g ]

Normal suburban community [not located n e a r industrial a c t i v i t y )

Urban r e s i d e n t i a l community [not immediately a d j a c e n t t o 0 heavily traveled roads and industrial areas)

Noisy urban residential community (near r e l a t i v e l y busy - 5 roads or i n d u s t r i a l areas]

Very n o i s y urban r e s i d e n t i a l community -10 Correction No prior experience with t h e i n t r u d i n g n o i s e +S f o r Previous

Community h a s had some previous exposure to i n t r u d i n g 0

Exposure

'

_{n o i s e but little e f f o r t is being made to control t h e noise.}

Community

Attitudes T h i s correction may a l s o be applied in a situation where

the communj.ty has n'ot been exposed to the n a i s e

previously, but t h e people a r e aware that bona f i d e e f f o r t s a r e b e i n g made to control t h e n s t s e

Community has had considerable previous exposure t o the

i n t r u d i n g n o i s e and t h e noise maker's relations with t h e community a r e good

Community aware that o p e r a t i o n causing n o i s e is v e r y necessary and it will n o t continue i n d e f i n i t e l y . This correction c a n b e a p p l i e d f o r a n o p e r a t i a n o f limited duration and under emergency circumstances

P u r e Tane Na pure tone or impulsive c h a r a c t e r or Impulse Pure t o n e o r impulsive c h a r a c t e r p r e s e n t

Description of microphone location at t h e measurement s i t e

S i t e

N o . Address Details

1 1309 Fernwood Drive 60 f t from centreline of J o f l n s t o n Road 2 Corncr of Johnston 40 Et from c e n t r e l i n e o f Johnston Road

Rd. and Albion Rd. 30 E t from centreline of Albion Road 3 3247 Clearwater C r . backyard

4 3364 Clearwater

CT.

front yard

5 3483 Southgate Road South facade; exposed to t r a f f i c on Bank Street and k l b i o n Road

6 2431 Bank S t r e e t 4 0 ft from edge o f Bank Street pave-

ment, a t Southway Motel

Note: I n all cases t h e microphone was l o c a t e d at a distance of approximately 6 ft from t h e b u i l d i n g facade and at a h e i g h t o f approximately 6 E t above t h e ground.

TABLE I14

Summary of average noise lcvcls measured at the monitoring s i t e s

Approximate

Daytime Level Nighttime Level Day- Night Approximate

(0700-2300 h r ) (2300-0700 h r ) Level Normalized

S i t e Ld ( i n dB) La (in dB) Ldn (in dB) Ld, ( i n dB)

Note 1: The d a t a at Site 6 were o b t a i n e d f o r slightly d i f f e r e n t time intervals t h a n t h o s e s p e c i f i e d , but this discrepancy

should not substanttally alter the results.

Note 2 : The second s e t s of d a t a (in parentheses) f o r Sites 3 a n d 5 are t h e average values excluding t h e exceptionally n o i s y intervals a t t r i b u t e d to a i r c r a f t movements.

COMMUHITY A E A C l 1 0 H

VIGOROUS ACTION me,.

.

e

SEVERbL THREATS OF

L E G A L ACT ION OR

STROMG APPEALS TO me* o m *

. *

-

LOCAL O F F I C I b L S T O STOP N O I S E WIDESPREbD C O M P L d l N T S OR SINGLE T H R E A T O F

:

• * a 3: = 0' L E G A L A C T I O N S P m n a l c COMPLAINT s N O REACTlOlJ ALTHOUGH N O I S E I S GENERALLY NOTICEABLE L d n - O U T D O O R D A Y / N I G H T S O U N D L E V E L O F I N T R U D I N G N O I S E I N dB COMMUNITY REACTION VIGOROUS A C T I O N S E V E R A L T H R E b T S OF L E G A L acrrm OR STRONG A P P E b L S T O L O C A L O F F I C I A L S TO S T O P N015E W I D E S P R E A D COMPLAINTS OR SIMGLE T H R E A T OF L E G A L A C T I O N S P O R A D I C C O M P L A l M T S

t

e m

1

NO R E A C T I O N ALTHOUGH

I

I

N O R M A L I Z E D O U T D O O R D A Y N I G H T S O U N D L E V E L OF I N T R U D I N G NOPSF I N dB F I G U R E 1 T Y P I C A L C O M M U N I T Y R E A C T I O N TO I N T R C I D I FJG N O I S E A F U N C T I O N O F ( a ) T H E O U T D O O R D A Y N i G H T L E V E L i L d i A N D f b \ T H E 4 O R M A L l Z E D I 1 D A Y N I S H T L E V E L ( F R O M R E F . 1 1 .

FIGURE 2

FIGURE 3 0 M E A S U R E D E Q U I V A L E N T 5 0 U N Q P R E S S U R E L E V E L S D U R I N G M O N I T O R I N G P E R I O D A T S I T E 1 ( 1 3 0 9 FERNWOOD D R I V E ) . FIGURE 3 t M E A S U R E D E Q U I V A L E N T S O U N D P R E S S U R E L E V E L 5 DURING M O N l l T O R I N G P E R 1 0 0 A T S I T E 2 ( C O R N E R OF _ I O H N S T O N R O A D A N D A L B I O W R O A D ) .

1

F R I D A Y 23 C E P T 2 4 S E P T F l G U R f 3 c MEASURED E O U l V A L E N T S O U N D P R E S S U R E L E V E L S D U R l N G M O N I T O R I N G P E R I O D A T S I T E 3 (3247 C L E A R W A T E R CP,.). 9 S A T U R D A Y 1 O C T 2 O C T 3 D C T F I G U R E 3 d M E A S U R E D E Q U I V A L E N T S O U N D P R E S S U R E L E V E L S D U R I N G M O N 1 T O R I N G P E R I O D A S S I T E 4 ( 3 3 6 4 C L E A R W A T E R C R . ) .

F I G U R E 3 e M E A S U R E D E Q U I V A L E N T S O U N D P R E S S U R E L E V E L S D U R I N G M O N I T O R I N G P E R I O D A T S L T E 5 ( 3 4 8 3 S O U T H G A T E R O A D ) . I W E D N E S D A Y

1

T H U R S D A Y F R I D A Y b O C T 7 O C T 8 O C T FIGURE 3 1 M E A S U R E D E Q U I V A L E N T SOUND P R E S S U R E L E V E L S OUR I N G M O N I T O R I N G n 7 n , - - - . - - . .- - - - -