10    Noise and vibration

10.1  Introduction and Methodology

This chapter presents the results of the traffic noise and vibration assessments.  The noise assessment generally follows that set out in the Design Manual for Roads and Bridges, Volume 11 (DMRB)(10.1).

The assessment has included an estimate of the number of residential properties within given distance bands for each option.  A brief noise survey was undertaken at various locations in June 2001(10.2).  (See Appendix 10).

The EC Framework Directive relevant to construction noise is 84/532/EEC on the approximation of the laws of the Member States relating to common provisions for construction plant and equipment (10.3).  This Directive is implemented under the EC Construction Plant and Equipment (Permissible Noise Levels) Regulations, 1988 and its amendments (10.4,10.5).

Noise regulations can be enforced by the Minister of the Environment under Section 106 of the Environmental Protection Agency (EPA) Act, 1992(10.6).  To date there are no national standards for noise emissions.  The Environmental Protection Agency did however publish a Guidance Note in 1995(10.7) on noise for the scheduled activities listed in the EPA Act, 1992 (sections 107 and 108).  Section 108 of the EPA Act, 1992 (Noise) Regulations, 1994(10.8) makes provisions for complaints to be made to the District Court in respect of noise which gives reasonable cause for annoyance.  Under section 107 of the Act, the EPA and local authorities are allowed the additional power to serve a Notice requiring measures to be taken to prevent or limit noise.

Section 77 of the Roads Act 1993 (10.9) enables the Minister for the Environment, following consultation with the Environmental Protection Agency, to introduce regulations requiring road authorities or the National Roads Authority, to carry out works to mitigate adverse effects caused by increased road traffic noise following construction of new roads or improvement of existing roads.  This section was commenced with effect from 1 August 1993 by the Roads Act, 1993 (Commencement Order 1993 (SI No. 197 of 1993).  No regulations have been made under it.

In assessing the impacts the following significance criteria have been used:

Impact

Significance Criteria

Severe adverse impact

 

Areas especially sensitive such as schools, hospitals, areas of local importance (e.g. outdoor areas commonly used by people where ambient noise levels are currently believed to be below 50 dB(A)) within 50m of the route.  Very high numbers of residential properties within 300m of route (excluding link roads) subject to traffic changes of greater than 25%.  Properties mainly located in quiet rural setting.

Major adverse impact

 

Areas especially sensitive within 50-100m of the route.  High number of residential properties within 300m of the route (excluding link roads) subject to traffic changes of greater than 25%.  Properties mainly located in quiet rural setting. 

Moderate adverse impact

 

Areas especially sensitive within 100-200m of the route.  Moderate numbers of residential properties within 300m of the route (excluding link roads) subject to traffic changes of greater than 25%.  Properties located in quiet rural setting and within settlements. 

Minor adverse impact

Areas especially sensitive within 200 -300m of the route.  Low numbers residential properties within 300m of the route (excluding link roads) subject to traffic changes of greater than 25%.  Properties located within settlements and quiet rural settings. 

No impact

No significant change for any properties within 300m of the route.

Minor beneficial impact

Reductions in noise levels at individual properties.

Moderate beneficial impact

Reductions in noise levels for individual properties and small settlements.

Major

Beneficial impact

Reduction in noise levels for significant number of residential properties in larger settlements. 

 

Properties have been identified from aerial photography (Summer 2000) taken at 20,000ft.  Commercial properties have been identified from the aerial photography and a windscreen survey.

 

10.2  Existing Situation

The number of properties adjacent to the existing N22, and therefore affected by roadside noise are presented in Table 10.1.  It should be noted that properties within Macroom itself have not been included for this count (between the R582 and the R618), and that these numbers are therefore an underestimate.

Table 10.1: Residential properties situated along the existing N22

 

0-50m

50-100m

100-200m

Total

Ballyvourney to Macroom*

240

89

115

444

Macroom to Ballincollig**

149

133

101

383

Whole Route

389

222

216

827

*    Property counts were undertaken from Ballyvourney to the N22 junction with the R582

** Property counts were undertaken from the N22 junction with the R618 to Ballincollig

 

Due to the current traffic flows on the existing roads and the proximity of dwellings and other noise sensitive receptors (e.g. schools etc.) to the road network, existing levels of noise are estimated to be high.

The majority of sensitive receptors within 300m of the existing N22 and the route options are residential properties (Table 10.4 and 10.5) though a number of commercial buildings (Table 10.6 and 10.7) also encompass the 300m envelope.

In order to define the existing noise climate, a brief noise survey was undertaken at various locations.  The noise survey results and details of measurement locations are presented in Appendix 10 and summarised below in Table 10.2.  The locations are shown on Figure 10.1.

Table 10.2 Ambient Noise Levels

Measurement point

Site location

National Grid Reference

Average LAeq dB

Average LA10 dB

Average LA90 dB

1

Local Road, north of Ballymakeery

121227, 077187

51

45

39

2

Local Road, between Clondrohid & Ballymakeery

125830, 077370

52

72

33

3

Ballyveerane Road

133868, 074220

64

73

43

4

R618 just east of Macroom

136497, 071988

67

68

44

5

Local road at Drombee

139211, 074190

50

50

38

6

R590 at N22 junction

142194, 066476

72

77

48

7

Local road at Beehive cross-roads

145211, 070782

48

49

39

8

N22 at Ovens

154922, 069944

76

81

59

NB:   -levels of less than 30dB(A) are not expected to cause disturbance in bedrooms at night-time
-levels of 40dB(A) or less during daytime are described by the World Health Organisation as a ‘good indoor noise climate’).

As can be seen from Table 10.2, the background LA90, which is a representation of the quietest 90% of the measurement time, is low and the noisiest 10% (LA10) (at sites 6 and 8) is influenced by existing road traffic.  However, as expected, away from existing roads, background noise levels in rural areas are low

10.3  Assessment of Effects: Construction and Operation

The assessment for each of the route options is based upon an estimate of the number of residential properties within distance bands (Tables 10.4 and 10.5) and the predicted impact on the existing noise climate within the region from the various route options (Table 10.3). The noise impacts of the routes are compared with existing ambient noise conditions. 

Table 10.3 Summary of Indicative noise impacts for design year (2029)

Route

Noise Increase dB(A)

Western Section (Nodes 1 to 6)

Yellow

- 5

Green

+23

Eastern Section (Nodes 6 to 16)

Yellow

  -4  to +25

Green

+24 to +25

Red

+20 to +21

Blue

+24 to +25

 

Noise levels along the proposed routes predicted using information from the traffic model and calculated using the methodology provided in the DMRB vol 11(1), indicate that for the design year (2029) between Ballyvourney and Macroom (western section), the Yellow route is likely to experience a decrease in noise levels from current ambient levels (currently high as the Yellow route runs along a similar alignment to the existing N22). The use of modern, thin, noise absorbing road surfaces on the new route would decrease the level of noise by 3-4dB(A).  The Green route however, would pass through a quiet rural area, with scattered villages and local roads. As the ambient noise level in this area is low, the noise increase is likely to be high (+ 23 dB(A)).

A similar situation is predicted to occur in the eastern section of the study area, with the Yellow route experiencing a decrease in noise levels for that section that follows the existing N22. At the eastern end of the study area, in the vicinity of the Curahaly Cross Roads (chainage 36,000) the proposed Yellow route deviates from the existing road, such that along this section the noise levels would be expected to increase from current ambient levels. The remaining routes would all experience an increase in noise levels, for the whole of their lengths. The greatest percentage increase is predicted for the Blue and Green routes, and the lowest for the Red route. The increase in noise levels for the combination routes have not been predicted, however, they are likely to lie between the routes of which they are composed:

·       Green/Link/Red route – the noise increase is likely to lie between 21 and 25 dB(A).

·       Yellow/Link 4/Blue route – the noise increase would be –4 dB(A) between Nodes 6 and 8, +25 dB(A), between Nodes 11 and 16, and between those levels between Nodes 8 to 11.

·       Yellow/Link6/Blue – noise levels would decrease by 3 dB(A) between Nodes 6 to 11 and up to the Curahaly Cross Roads. From the Curahaly Cross Roads up to node 12, between Nodes 12 to 12a up to Node 16, the noise levels would increase by +25 dB(A).

Further detail on indicative noise impacts are presented in Appendix 10.

 

Table 10.4 Western Route Option assessment - residential buildings within 300m of the centreline for proposed routes

 

 

0-50

50-100

100-200

200-300

Total

Overall total

Green

N22 – Ballyvourney
(Nodes 1 to 3)

1

2

4

6

13

107

 

Ballyvourney – Ballyveerane junction (Nodes 3 to 6)

2

16

39

37

94

Green/Link/Yellow

N22 – Ballyvourney
(Nodes 1 to 3)

1

2

4

6

13

143

 

Ballyvourney – Ballyveerane junction (Nodes 3 to 6)

2

11

57

60

130

Yellow

N22 – Ballyvourney
(Nodes 1 to 3)

0

4

3

5

12

252

 

Ballyvourney – Ballyveerane junction (Nodes 3 to 6)

10

30

62

138

240

 

Table 10.5 Eastern Route Option assessment - residential buildings within 300m of the centreline for proposed routes

 

 

0-50

50-100

100-200

200-300

Total

Overall total

Green

Ballyveerane junction -Ballincollig bypass
(Nodes 6 to 16)

7

34

66

59

166

166

Red

Ballyveerane junction-Ballincollig bypass
(Nodes 6 to 16)

14

43

89

111

257

257

Green/Link/Red

Ballyveerane junction-Ballincollig bypass
(Nodes 6 to 16)

8

30

66

79

183

183

Yellow

Ballyveerane junction- R590/R585 junction
(Nodes 6 to 11)

5

42

87

65

199

398

 

R590/R585 junction – Ballincollig bypass
(Nodes 11 to 16)

12

48

90

49

199

Yellow/Link4/Blue

Ballyveerane junction- R590/R585 junction
(Nodes 6 to 11)

4

34

73

61

172

355

 

R590/R585 junction – Ballincollig bypass
(Nodes 11 to 16)

7

31

69

76

183

Yellow/Link6/Blue

Ballyveerane junction- R590/R585 junction
(Nodes 6 to 11)

5

42

87

65

199

377

 

R590/R585 junction – Ballincollig bypass
(Nodes 11 to 16)

4

44

83

47

178

Blue

Ballyveerane junction- R590/R585 junction
(Nodes 6 to 11)

12

10

33

48

103

286

 

R590/R585 junction – Ballincollig bypass
(Nodes 11 to 16)

7

31

69

79

183

 

In addition, a number of commercial premises and community facilities (such as schools, churches and sports grounds) have also been identified:

 

Table 10.6 Western Route Option assessment - commercial properties and community facilities within 300m of the centreline for proposed routes

 

 

0-50

50-100

100-200

200-300

Total

Overall total

Green

N22 – Ballyvourney
(Nodes 1 to 3)

0

0

0

0

0

6

 

Ballyvourney – Ballyveerane junction (Nodes 3 to 6)

0

1

3

2

6

Green/Link/Yellow

N22 – Ballyvourney
(Nodes 1 to 3)

0

0

0

0

0

2

 

Ballyvourney – Ballyveerane junction (Nodes 3 to 6)

1

0

0

1

2

 

Yellow

N22 – Ballyvourney
(Nodes 1 to 3)

0

0

0

0

0

22

 

Ballyvourney – Ballyveerane junction (Nodes 3 to 6)

4

2

2

14

22

 

Table 10.7 Eastern Route Option assessment - buildings and community facilities within 300m of the centreline of proposed routes

 

 

0-50

50-100

100-200

200-300

Total

Overall total

Green

Ballyveerane junction -Ballincollig bypass
(Nodes 6 to 16)

1

0

3

2

6

 

Red

Ballyveerane junction -Ballincollig bypass
(Nodes 6 to 16)

 

0

1

2

6

9

 

Green/Link/Red

Ballyveerane junction -Ballincollig bypass
(Nodes 6 to 16)

0

1

2

3

6

 

Yellow

Ballyveerane junction - R590/R585 junction
(Nodes 6 to 11)

1

5

5

6

17

36

 

R590/R585 junction – Ballincollig bypass
(Nodes 11 to 16)

0

1

12

6

19

Yellow/Link4/Blue

Ballyveerane junction - R590/R585 junction
(Nodes 6 to 11)

1

1

2

6

10

25

 

R590/R585 junction – Ballincollig bypass
(Nodes 11 to 16)

0

4

10

1

15

Yellow/Link6/Blue

Ballyveerane junction - R590/R585 junction
(Nodes 6 to 11)

1

5

5

6

17

31

 

R590/R585 junction – Ballincollig bypass
(Nodes 11 to 16)

0

1

12

1

14

Blue

Ballyveerane junction - R590/R585 junction
(Nodes 6 to 11)

0

0

2

1

3

18

 

R590/R585 junction – Ballincollig bypass
(Nodes 11 to 16)

0

4

10

1

15

 

For the western section of the study area, i.e. between Ballyvourney and Macroom, the Green and Green/Link/Yellow routes would be likely to cause a similar level of noise disturbance, as although the Green route would have fewest properties along its length overall, the Green/Link/Yellow route would have fewest properties within the closest distance bands (0-100m).  The Green/Link/Yellow route would also have the fewest commercial properties and community facilities along its length.  The Yellow route, situated on a similar alignment to the existing N22, would have the greatest number of residential properties, (both overall, and within 100m of the route) and also the greatest number of commercial properties and community facilities along its length.

For the Eastern section, Table 10.5 indicates that between Macroom and Ballincollig, the Green and the Green/Link/Red routes have the least potential of causing widespread noise disturbance.  The Yellow route would substantially affect a greater number of households overall, and within the closest distance band (0-100m) than the rest of the route options.  The greatest number of commercial properties occurs along the Yellow route, although this is nearly matched by the number along the Yellow/Link4/Blue routes (Table 10.7).  There are also a number of community facilities including Clough Dubh National School and St Joseph’s church, both within 200m of the Blue and the Yellow/Link 6/Blue route. The Knockanemore National School lies within 200m and St John’s Church and Éire Óg GAA Club within 300m of the Yellow route.

 

Green Route

Nodes 1 to 6

Minor Adverse Impact - Noise levels would increase by 23 dB.  There are 107 residential properties within this section, some situated within the settlements of Ballyvourney and Clondrohid, and some in a quiet rural setting.  Clondrohid Community Hall is situated within 200m of the route

Nodes 6 to 16

Major Adverse Impact - Noise levels would increase by 24-25 dB over this stretch.  There are 166 properties within this section (6.8 per km) situated within a quiet rural setting

Yellow Route

Nodes 1 to 6

Major Beneficial Impact - Noise levels would decrease by 5 dB.  There are 242 residential properties within this section, situated in the outskirts of Macroom, within the settlement of Ballyvourney and along the existing N22.

Nodes 6 to 11

Major Beneficial Impact - Noise levels would decrease by between 3 and 4 dB.  There are 199 residential properties within this section (14.9 per km), mainly situated on the eastern outskirts of Macroom, in Lissardagh and along the existing N22.

Nodes 11 to 16

Moderate Adverse Impact - Noise levels would decrease by 3 dB from Node 11 up to Curahaly Cross Roads, but would increase by 25 dB for the remainder of the length.  There are 199 residential properties within this section (11.2 per km) mainly situated along the existing N22, and in small settlements.  The route would also run within 200m of the Knockanemore National School and within 300 m of the Éire Óg GAA Club, and the St John’s Catholic Church in Knockanemore.

Red Route

Nodes 6 to 16

Moderate Adverse Impact - Noise levels would increase by 20 dB.  There would be 257 residential properties within this section (11.0 per km), situated in the settlement of Macroom and some situated within a quiet rural setting.  The Canovee National School would be situated within 200m of the route.

Blue Route

Nodes 6 to 11

Moderate Adverse Impact - Noise levels would increase by 25 dB.  There would be 103 residential properties within this section (8.5 per km) some situated within Macroom and some situated within a quiet rural setting.

Nodes 11 to 16

Moderate Adverse Impact - Noise levels would increase by 25 dB.  There would be 183 residential properties within this section (13.0 per km) located within settlements (Crookstown, Cloughduv, Aherla, Killumney) and quiet rural settings.  Cloughduv National School and St Joseph’s Church would be situated within 200m of the route.

Link Routes

Green/Link/Yellow, Nodes 3 to 6

Major Adverse Impact - Noise levels would increase by 23 dB between Nodes 3 and 4, and would decrease by 5 dB between Nodes 5 and 6.  The increase/decrease in noise levels between Nodes 4 and 5 cannot be predicted at this time, although overall the change in noise levels for this route is likely to be between that experienced by the Green and the Yellow routes (Nodes 3 to 6).  There would be 130 residential properties within this section, (8.5 per km) located within quiet rural settings.

Green/Link/Red, Nodes 6 to 16

Major Adverse Impact - Noise levels would increase by between 25 dB between Nodes 6 and 9, and by 21 dB between Nodes 13 and 16.  The increase/decrease in noise levels between Nodes 9 and 13 cannot be predicted at this time, although overall the change in noise levels for this route is likely to be between that experienced by the Green and the Red routes (Nodes 6 to 16).  There would be 183 residential properties along this route (7.6/km) located within a quiet rural setting.

Yellow/Link4/Blue, Nodes 6 to 11

Minor Adverse Impact - Noise levels would decrease by 3 dB between Nodes 6 and 8, and would increase by 25 dB between Nodes 10 and 11.  The increase/decrease in noise levels between Nodes 8 and 10 cannot be predicted at this time, although overall the change in noise levels for this route is likely to be between that experienced by the Yellow and the Blue routes (Nodes 6 to 11).  There are 172 residential properties along this route (13.0 per km) located within settlements and along the existing N22.

Yellow/Link6/Blue, Nodes 11 to 16

Moderate Adverse Impact - Noise levels would decrease by 3 dB between Nodes 11 and Curahaly Cross Roads, and would increase by 25 dB between Nodes 12a and 16.  The increase/decrease in noise levels between Nodes 12 and 12a cannot be predicted at this time, although overall the change in noise levels for this route is likely to be similar to that predicted for the (Nodes 12a to 16).  There would be 178 properties along this route (12.8 per km) some located in a quiet rural setting, some along the existing N22, and some within settlements.  Cloughduv National School and St Joseph’s Church would be situated within 200m of the route.

 

10.3.1              Vibration

Traffic generated vibration can arise as ground-borne vibration resulting from the combined effects of vehicle axle-loading and road surface discontinuities, or airborne vibrations resulting mainly from low frequency noise from engines and exhausts causing detectable vibration to arise in building elements such as windows and doors.

Generally, ground-borne vibrations occur on older roads such as the existing network.  The even surface of the scheme, together with the increased distance from the majority of the residential properties would, when compared with the existing situation, tend to maintain levels of vibration below the threshold of detection.

 

10.3.2              Construction Noise and Vibration

At this stage, details on the phasing of construction works, the number of construction plant, site compound locations, piling etc is not formulated and therefore the potential construction noise and vibration impact cannot be assessed.  Once the above construction details are finalised for the preferred route an assessment will be undertaken for construction related activity.

 

10.4 Mitigation Proposals

The potential impact from road traffic noise can be reduced by natural screening, noise fences (which can reduce noise levels by 3-7dB(A)), false cuttings and landscaping.  Route specific mitigation has not been identified at this stage, however measures would be included in the detailed design for the proposed route where appropriate. 

 

10.5 Conclusion

10.5.1              West of Macroom

Between Ballyvourney and Macroom, overall the preferred route is Yellow, as although there are high numbers of residential properties within 300m of the route, traffic flows between Ballyvourney and the R582 junction indicated that the noise impact on these properties is likely to decrease.  This is due to the fact that currently the properties would generally be adjacent to the existing road, which less traffic would use, than to the proposed new route.  The existing N22 runs close to the proposed Yellow route and the noise absorbing capabilities of modern road surfaces are likely to decrease the noise levels experienced by these properties.  In addition, the number of properties adjacent to the proposed Yellow route would be fewer than those alongside the existing N22, reducing the number of properties affected by noise from the road. The level of noise likely to be experienced by properties within 300m of the Green or Green/Link/Yellow routes are likely to increase, by up to 24 dB(A) in comparison to ambient noise levels. These routes are therefore least preferred for this section west of Macroom.  However, between Nodes 1 and 3, the Yellow and Green routes run very close to each other.  Although no traffic flows area available for this specific stretch of the road, it is likely that there would be very little difference in traffic flows, and hence noise levels, between the routes.  Therefore, between Nodes 1 and 3, the Green and Yellow routes would be equally preferred.

 

10.5.2              East of Macroom

Between Macroom and Ballincollig, of the northern routes (Green, Red and Green/Link/Red routes), the Red route would have the least impact on ambient noise levels.  The Green and the Green/Link/Red routes would have a major adverse impact as they pass through quiet rural areas, whereas the Red route also passes close by the settlement of Macroom.  The Red route would have the greatest number of properties along its length, of these three routes, both overall, and within the closest distance band 0-100m.  The Green route, which has the lowest number of properties along its length, but would have the greatest noise increase from ambient levels.  Although the Red route would have the greatest number of properties along its length, it would be the preferred option of the northern routes, as the increase in noise levels, from existing ambient levels would be minimised.

The southern routes (Blue, Yellow and Yellow/Link routes) all meet at Node 11.  Therefore these routes can be divided into two sections, i.e. between Nodes 6 and 11, and between Nodes 11 and 16.  Between Nodes 6 and 11, the Yellow route would demonstrate a decrease in ambient noise levels (decrease of between 3 and 4 dB), having a major beneficial impact, whereas the Blue route would demonstrate an increase in ambient noise levels (between 24 and 25 dB) and have a moderate adverse impact.  The Yellow/Link4/Blue route would be likely to demonstrate an increase in noise levels between those of the Yellow and the Blue routes.  The decrease in ambient noise levels along the Yellow route would benefit a large number of receptors that already experience high levels of traffic noise (from the existing N22).  The great majority of these properties are situated close to the existing N22 and already experience impact from traffic noise.

The Yellow route would therefore have a moderate/major beneficial impact and would be the preferred route.

Between Nodes 11 and 16 the ambient noise levels along the part of the Yellow route (up to Curahaly Cross Roads) are predicted to decrease for 2009 and 2029, although an increase of 25 dB is predicted for the remainder of the route, so that overall this would have a moderate adverse impact. The noise levels for both the Blue route, and the Yellow/Link6/Blue routes are predicted to increase, and both would have a moderate adverse impact. The number of properties within 300m of the Yellow route is slightly greater than alongside the other two routes.  Whilst all route options between Nodes 11 and 16 would pass within 200m of potentially sensitive receptors and are predicted to have a moderate adverse impact, the Yellow route would be the marginally less preferred route between Nodes 11 to 16, as it would pass within 300m of a slightly greater number of residential properties and potentially sensitive locations than the Blue and Yellow/Link6/Blue routes. The Blue and Yellow/Link6/Blue routes would be equally preferred. 

Overall, the preferred southern route, between nodes 6 to 16 would be the Yellow/Link6/Blue route.

When the preferred northern route (Red) and the preferred southern route (Yellow/Link6/Blue) are compared, the Yellow/Link6/Blue route would be the preferred route overall, due to the predicted decrease in ambient noise levels along the majority of its length which would benefit a large number of properties.

10.6 References

10.1 Department of Transport (1998).  Design Manual for Roads and Bridges, Volume 11 (revised February 1998)

10.2 Biospherics 2001.  N22 Road Project.  Report on Site Noise Levels.  Ref 290

10.3 Council Directive 84/532/EEC of 17 September 1984 on the approximation of the laws of the Member States relating to common provisions for construction plant and equipment

10.4 European Communities (Construction Plant and Equipment)(Permissible Noise Levels) (Amendment) Regulations, 1990

10.5 European Communities (Construction Plant and Equipment)(Permissible Noise Levels)(Amendment) Regulations, 1996

10.6 The Environmental Protection Agency (EPA) Act, 1992 (Sections 106, 107, 108)

10.7 EPA Guidance Note 1995

10.8 The Environmental Protection Agency Act, 1992 (Noise) Regulations, 1994 (SI No. 179 of 1994)

10.9 Roads Act, 1993 (Section 77)

 

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