14 Traffic Noise and Vibration
14.1.1 This section presents the DMRB Stage 2 assessment of the potential noise and vibration impacts of the Forth Replacement Crossing.
14.1.2 The assessment builds on the Strategic Environmental Assessment (Jacobs et al., 2007) that considered noise and vibration and informed the decision by the Scottish Ministers to progress a new crossing by bridge in the location currently proposed.
14.1.3 Appendix A14.1 presents an introduction to noise and vibration as well as standard noise terms.
14.2 Approach and Methods
Road Traffic Noise and Vibration
14.2.1 The assessment and mitigation of road traffic noise is carried out according to established prediction and assessment methodologies governed by various regulatory standards. Key documents include:
- Calculation of Road Traffic Noise (CRTN). The UK calculation method for predicting road traffic noise levels. Department of Transport (1988).
- Design Manual for Roads and Bridges (DMRB), Volume 11, Part 7. Includes guidance and assessment methods for noise and vibration. DMRB is adopted by Transport Scotland for new trunk road schemes.
- The Environmental Impact Assessment (Scotland) Regulations 1999 (as amended).
- Noise Insulation (Scotland) Regulations 1975. The Noise Insulation Regulations define the conditions under which dwellings are eligible for noise insulation to control internal noise levels. The number of properties that are likely to be eligible for statutory insulation would be indicated as part of a Stage 3 level assessment. Noise mitigation measures would be applied, if practicable, to ensure that noise exposure at dwellings alongside the Forth Replacement Crossing is controlled below the qualifying threshold for The Noise Insulation (Scotland) Regulations.
Construction Noise and Vibration
14.2.2 Construction noise and vibration is temporary and, as is accepted practice, should not be assessed in the same way as permanent operational impacts such as traffic noise. It is recognised that this must be judged against local needs and conditions. The impact of construction noise and vibration is usually assessed with reference to the following guidance and statutes:
- BS 5228: Noise and Vibration Control on Construction and Open Sites (British Standards Institution, 1997). BS 5228 provides guidance on the assessment and control of noise from construction operations to minimise the impact on local residents and construction workers.
- Environmental Protection Act (1990). The EPA describes the duty of the Local Authority to take steps to identify and abate any noise, including that from a construction site, deemed to be causing a statutory nuisance.
- Control of Pollution Act (1974). CoPA gives the Local Authority powers to serve a notice requiring the control of site noise and the mechanism by which persons responsible for premises can seek advance approval for construction activities and the associated steps to minimise noise.
- Local Policies. Local requirements for construction noise and vibration control are often set by Local Authorities. Identification of local policies would be pursued as part of the ongoing consultation process and developed in further detail during Stage 3 assessment. Noise limit targets are often based on recognised limits published many years ago in advisory documents such as DoE Advisory Leaflet (AL) 72 (1976). Advisory Leaflet (AL) 72 recommends that daytime construction noise levels at the facades of noise sensitive receivers should not exceed:
i. 75 dB LAeq,12h in urban areas near to main roads or in heavy industrial areas; or
ii. 70 dB LAeq,12h in rural, suburban and urban areas away from road traffic and industrial noise.
14.2.3 It is also proposed in AL 72 that noise limits should be 10 dB(A) lower for the evening period.
14.2.4 Chapter 17 (Disruption Due to Construction) provides more information on the construction process and its effects in terms of other environmental parameters.
Identification of Noise Sensitive Locations
14.2.5 It is a requirement of the Stage 2 DMRB procedure for the noise assessment to determine the numbers of noise sensitive properties in distance bands of 0-50m, 50-100m, 100-200m, and 200-300m from each of the route corridor options. To provide additional information, these property counts were extended to include 300-400m, 400-500m and 500-600m. A 600m area will also be considered during detailed assessment at Stage 3.
14.2.6 Potentially noise sensitive properties include residential properties, care homes, schools and hospitals. These were identified through review of existing information from previous studies and from review of Ordnance Survey plans. The distance bands are shown on Figures 14.2 to 14.9.
Assessment Methodology for Road Traffic Noise and Vibration
Road Traffic Noise
14.2.7 This assessment has been undertaken in accordance with DMRB (1994) guidance of comparing the noise levels for the Do Something scenario (with Forth Replacement Crossing) against noise levels for the Do Minimum scenario (continued use of the Forth Road Bridge). The method requires that comparisons are made between the ambient noise situation (before the change produced by the Forth Replacement Crossing) and the noise level in the worst-case year in the first 15 years after opening (i.e. generally the design year which would have the maximum traffic flow 15 years after opening). The DMRB (1994) methodology was current guidance at the time of the study but an updated (2008) version was issued in August (HA 213/08) and this will be used for the next stage of assessment.
14.2.8 For the purposes of this assessment, the ambient and design years are taken as 2017 (i.e. the proposed year of opening) and 2032 respectively.
14.2.9 The calculations are carried out according to the CRTN methodology using proprietary software. Traffic noise levels are calculated across a grid of receiver positions over the study area, which includes traffic flows from the bridge itself, and contours of noise level exposure are established.
14.2.10 The current DMRB defines a study area of 300m either side of the route corridor options for Stage 2 assessment. However this chapter presents information for a wider area to provide additional information. The absolute noise levels (as mapped on Figures 14.1 to 14.5) extend to 500m either side of each route corridor. Potential impacts on noise sensitive receptors are reported in terms of predicted noise level changes (as mapped on Figures 14.6 to 14.9).
14.2.11 Noise levels are calculated in terms of the LA10,18h index as specified in CRTN. This represents the A-weighted noise level exceeded for 10% of the time between the hours of 06:00 and 00:00. For this study, annual average weekday traffic (AAWT) flows have been used as specified by CRTN. The traffic flow predictions on which the noise calculations are derived have been provided by traffic engineers for the different route corridor options.
14.2.12 In addition to traffic flow information, the traffic noise calculations are determined from digital mapping data detailing topographical and landscaping information including man-made features; positions of noise sensitive receivers such as houses, schools and hospitals; type of ground cover; and type of road surface used.
14.2.13 Based on the assessed effects, the likely requirement for noise mitigation associated with each route corridor option would be compared as required by the DMRB Stage 2 methodology.
Road Traffic Vibration
14.2.14 DMRB recommends that in addition to an assessment of noise, the effects of vibration should also be considered where possible. In the case of ground-borne vibration, the likelihood of perceptible vibration being caused is particularly dependent upon the smoothness of the road surface. Research has shown that vibration levels caused by heavy goods vehicles travelling at 110kph over a 25mm hump could cause perceptible vibration at up to 40m from the road. This would infer, therefore, that it is unlikely that significant levels of vibration would be generated at distances greater than this.
14.2.15 The DMRB method for estimating the likelihood of airborne noise causing vibration nuisance is based upon studies close to main roads where such problems can occur. These studies were limited to receivers within 40m of the road without screening. As an indication of the scale of impact relative to noise effects, the guidance in DMRB states that for a given level of traffic noise exposure the percentage of people bothered very much or quite a lot by airborne vibration is 10% lower than the corresponding amount for noise nuisance. Also, the significance of any change in airborne traffic vibration can be considered proportional to the significance of changes in traffic noise, as described above for each area.
14.2.16 The impact of vibration effects has been examined within the constraints of the assessment methodology as defined above.
Assessment Methodology for Construction Noise and Vibration
14.2.17 At this stage of the project (route corridor options assessment), detailed construction methodologies have not been developed. Therefore, for the Stage 2 assessment, the construction noise and vibration effects for the Forth Replacement Crossing have been assessed by considering the likely range of construction processes associated with the Forth Replacement Crossing works and their typical durations.
14.2.18 The noise effects associated with construction works for the mainline are estimated from a detailed predictive study that has recently been undertaken by Arup for another major highway scheme (M1 J21-30 widening; Highways Agency, 2006).
14.2.19 For the purposes of the noise assessment, the mainline construction activities (i.e. proposed new and upgraded roads) are categorised into four major phases as follows:
- site clearance;
- earthworks (and piling);
- drainage / lighting;
- pavement construction.
14.2.20 As part of the M1 J21-30 Widening referred to in paragraph 14.2.15, a range of noise levels was calculated across representative receivers closest to each route corridor option for each of these phases. The noise sensitive receivers alongside the route corridor were selected within a distance range typically 20 — 50m from the scheme (i.e. those potentially the worst affected). Piling operations were also considered as a separate activity, as might take place during retaining wall constructions, as this is known to be a potentially noisy operation. This would only occur for a limited number of situations along the mainline.
14.2.21 The calculations carried out for the M1 J21-30 Widening study were based on the plant machinery typically involved for these operations (as agreed with the engineers for that scheme) and the rate of progress past each receiver location along the route corridor. The results represent a worst-case day when the particular operation is passing directly alongside the receiver. The daily noise levels would be lower as each phase of works approaches and also passes beyond the receiver. Table 14.1 gives the highest noise levels calculated for each operation at the closest nearby receivers (approximately 20m).
14.2.22 The data provide an illustration of the highest daily noise levels at a reference distance during highway construction. Although these results are not specific to the construction of the Forth Replacement Crossing, the data can be used as an indication of noise levels at receivers close to the northern and southern route corridor options.
Table 14.1: Example ‘Worst-case Day’ Noise Level from Construction Phases
Example Noise Levels from Construction Phases dB LAeq,10h façade corrected
Receiver Locations approx 20m from Highway Scheme
(first floor noise level without screening potentially provided by early installation of operational mitigation)
(Taken from: Highways Agency (2006) Widening the M1 J21-30 Environmental Statement of Contract 1 works (Junctions 25-28))
Drainage and Lighting
14.2.23 Based on the assessed effects, the appropriate best practicable means mitigation has been proposed.
Evaluation and Significance Criteria
Road Traffic Noise
14.2.24 There is no established UK guidance which clearly defines significance criteria for the assessment of changes in road traffic noise. The response of people to noise is highly subjective and sensitivity to changes in traffic noise change is therefore variable across the population. Part 7, Volume 11 of DMRB (The Highways Agency et al., 1994) notes that ‘attitudes to traffic noise are also related to satisfaction with the neighbourhood in general’. Given the variability of response and the potential for non-acoustical factors to influence perceptions of noise, any assessment of significance can only represent an average community response to traffic noise. Many of the guidance documents (past and present) relating to traffic noise assessment note that a change of less than 3dB(A) is not generally perceptible and it would follow that a significant effect cannot occur if the change is not perceptible. Further to this, just because a change is perceptible does not necessarily mean that this change is sufficient to cause a significant effect. Nevertheless, a change threshold of 3dB(A) has commonly been used in traffic noise assessments in the UK to approximate the threshold of significance.
14.2.25 For reference, the guidance citing the 3dB(A) threshold includes:
- Transport Scotland (2008), Scottish Transport Appraisal Guidance — The Noise Objective, STAG Unit 3.3.2, HMSO
- Department For Transport (1998), A New Deal For Trunk Roads In England: Guidance On The New Approach To Appraisal, HMSO
- Department Of The Environment (1990), Report Of The Noise Review Working Party, HMSO
- Institute Of Environmental Assessment (1992), Guidelines For The Environmental Assessment Of Road Traffic. IEA
- The Scottish Office, Development Department (1999), Planning Advice Note 56, Planning and Noise
14.2.26 However, DMRB states that, following a change in traffic flow, benefits or disbenefits have been reported for traffic noise changes as small as 1dB(A). This is based on research of community response to noise indicating that people would be more sensitive to the abrupt noise change soon after opening of the Forth Replacement Crossing and for a number of years afterwards.
14.2.27 DMRB describes a procedure for assessing noise nuisance experienced alongside the highway. Noise changes of 1dB(A) or more are related to the estimated change in the ‘percentage of people bothered very much or quite a lot by traffic noise’. Although the DMRB method does not rate the noise change in terms of the significance of the effect, it suggests that a proportion of the community may report a change in nuisance level following noise changes as small as 1dB(A). DMRB states that this heightened sensitivity is a temporary effect and the longer-term noise nuisance level after a number of years is assumed to revert to the ‘steady state’ level.
14.2.28 When considering appropriate significance criteria for changes in traffic noise, it is widely accepted that changes of 3dB(A) or more would generally be noticeable, whilst the research cited in DMRB indicates that some individuals would respond to changes less than this, particularly soon after opening of the road. In the case of small changes in noise levels considerably less than 3dB, which would not generally be regarded as perceptible, it could be argued that the rating of nuisance changes may be coloured by factors other than noise (Baughan & Huddart, 1993).
14.2.29 For the purposes of this assessment it is assumed that significant effects would be generally experienced for changes of 3dB(A) or more at residential properties. Clearly this threshold cannot represent an absolute step-change in people’s response and it follows that for some proportion of the community noise changes less than 3dB(A) could be perceptible. It would be recognised, therefore, that for some people there could be an onset of significant change for changes between 2 and 3dB(A). Significance of noise change at non-residential receptors would be based on these same criteria, although other factors may affect the assessment, such as the exact nature of use, the times of use and the sensitivity of the occupants (eg special educational needs). Due to the complexity of the various issues a qualitative judgement on the significance of noise change was made for these non-residential receptors. The effects on non-residential receptors will be considered in more detail at the next assessment stage.
14.2.30 The following semantic scale is commonly used in traffic noise assessment to broadly rate the magnitude of the noise effects.
Table 14.2: Significance Criteria for Changes in Traffic Noise
Change in Noise Level
Magnitude of Effect
Significance of Effect
5 to <10
3 to <5
1 to <3
<1 to >-1
-1 to >-3
-3 to >-5
-5 to >-10
14.2.31 Section 14.4 will primarily consider noise changes based on the change between the ambient noise situation and the noise level in the worst-case year in the first 15 years after opening (i.e. 2032) as required by DMRB.
14.2.32 There are no nationally accepted criteria by which to assess the significance of effects caused by exposure to construction noise. The guidance documents available do not propose any specific criteria for the setting of noise limits or significance criteria for construction works. When assessing construction noise the guidance in BS 5228 identifies a number of key factors in relation to the acceptability of noise (and vibration) to people living and working around the site. Because the noise changes are temporary, the duration of the noise exposure is an important factor as well as the actual noise level.
14.2.33 An initial assessment of the significance of the effects has been made based on the predicted noise levels relative to the ambient levels and the duration of exposure.
14.2.34 As a basic indicator of temporary significant effects for the purpose of the Stage 2 assessment, an outline significance criteria would be defined as an increase in the LAeq,10h at affected dwellings as a result of construction by at least 3dB (i.e. perceptible) for a period of at least 8 weeks.
Limitations to Assessment
14.2.35 The assessment of road traffic noise effects is based on the data and information provided by others, i.e. traffic model, road design details and topography. However, it is considered that all data inputs required for the Stage 2 assessment have been obtained to an adequate level of detail.
14.2.36 The assessment of construction noise has been based on the anticipated construction stages to complete the required works. It is possible that the exact plant and duration of activities would vary slightly from the assumptions made although it is considered that the assumptions made are representative of the likely works. The level of information currently available for the assessment of construction noise for the Forth Replacement Crossing is limited. However, at this outline design stage it is considered that the examination of the intensity and likely duration of works would be sufficient to identify the potential for significant effects. Construction noise and vibration impacts would be considered in greater depth at the detailed assessment stage.
14.3 Baseline Conditions
Ambient Noise Climate
14.3.1 For the purposes of the noise assessment, the baseline situation is represented by the predicted ambient noise levels before the change produced by the Forth Replacement Crossing as required by DMRB. This is taken as the noise levels from the existing roads in the year 2017. Figure 14.1 shows noise levels at 5dB intervals to represent the ambient situation in 2017, illustrating noise contour maps for the existing roads. The contour maps (Figure 14.1) show the noise exposures within the study area from which the effects of distance, topography, the presence of noise barriers and other screening structures can be seen.
Distribution of Noise Sensitive Locations
14.3.2 Table 14.3 presents the numbers of noise sensitive receptors (this includes residential, care homes, schools and hospitals) identified within distance bands from each of the route corridor options.
Table 14.3: Numbers of Noise Sensitive Receptors in Different Distance Bands from the Forth Replacement Crossing Route Corridor Options
Forth Replacement Crossing
Number of noise sensitive receptors
0 — 50m
North Corridor Option 1
North Corridor Option 2
South Corridor Option 1
South Corridor Option 2
14.3.3 This table gives numbers of noise sensitive receptors up to 600m from the Forth Replacement Crossing route corridor options. As the current DMRB specifies that properties in bands up to 300m should be considered, it is the 300m results which would primarily be considered in this report as the noise effects would be expected to be greatest within this distance.
14.3.4 It must be noted that property counts of this nature cannot be taken as a definitive indication of noise impact, as they represent only the numbers of properties in close proximity to the route corridor options and cannot therefore take account of actual noise exposure or noise sources elsewhere in the study area which may affect the assessment.
14.3.5 It should be assumed that, unless otherwise stated, all properties in the study area are already subject to road traffic noise, which is likely to lessen noise change, and hence impact, arising from the Forth Replacement Crossing.
14.3.6 For the two northern route corridor options under consideration, there is a reduction of properties within both route corridors relative to the existing alignment (both route corridor options are further from North Queensferry). North Corridor Option 2 provides the greatest reduction in numbers of properties affected. Of the two, North Corridor Option 2 minimises the numbers of properties in the closest bands i.e. 0-100m and 100-200m.
14.3.7 For the southern route corridor options, again, both of the corridor options show a reduction of properties within the route corridor relative to the existing alignment. South Corridor Option 2 provides the greatest reduction in numbers of properties affected, as the route corridor takes the M90 southward, away from the southern South Queensferry residential areas, whilst at the same time, traffic along the A904 (Builyeon Road) is also reduced.
14.3.8 There are six schools within the vicinity of the Do-Minimum route: one (Inverkeithing High School) in the 0-50m band; one in the 50-100m band (Park Road Primary School); one (Inverkeithing Nursey) in the 100-200m band; one (Inverkeithing Primary School) in the 200-300m band; one (Careshare Nursery) in the 300-400m band and one (North Queensferry Primary School) in the 500-600m band as shown on Figure 14.1.
14.3.9 There are four schools within the vicinity of the existing route: one (Dalmeny Primary School) in the 50-100m band; two (Echline Primary School and Kirkliston Primary School) in the 300-400m band; and one (Queensferry Primary School) in the 500-600m band. There is also one care home (Leonard Cheshire Home, Kirkliston) within the 300-400m band.
14.4 Potential Impacts
14.4.1 This section describes the changes in noise levels predicted at representative locations as a result of the construction works and the operation of the Forth Replacement Crossing route corridor options. Representative noise sensitive receptors are identified on Figures 14.1 to 14.9 and discussed in this section. It should be noted that potential impacts are reported (i.e. with no mitigation). Mitigation is then considered in Section 14.5 for both construction and operational noise to address potential noise impacts.
14.4.2 Figures 14.1 to 14.5 show predicted absolute noise levels for the do minimum (ambient) situation in 2017 and with the operation of the Forth Replacement Crossing in the opening (2017) and design years (2032). Figures 14.6 to 14.9 show those locations where there are predicted to be noise changes of 1dB(A) or more at noise sensitive receivers. Based on the significance criteria set out earlier, it would be assumed that significant effects would be generally experienced for changes of 3dB(A) or more.
14.4.3 It should be noted that the noise contour results shown in these figures do not take into account the effect of façade reflections which result in a localised increase of 2.5dB(A) at one metre in front of a building’s façade.
14.4.4 With regard to ground-borne vibration, it is considered that no properties are sufficiently close to the Forth Replacement Crossing for significant ground-borne vibration impacts to occur. This is because the surface of the proposed new and upgraded roads would be smooth, with no surface irregularities of sufficient size to generate significant levels of ground-borne vibration. The size of irregularities necessary to cause perceptible ground-borne vibration is discussed in the assessment methodology described in Section 14.2.
14.4.5 In the case of airborne vibration, the guidance suggests that the percentage of people bothered very much or quite a lot by airborne vibration is 10% lower than the corresponding amount for noise nuisance. It can be assumed then that significant effects associated with airborne vibration would be approximately equivalent to, but no greater than those effects reported for noise.
14.4.6 For the reasons set out in paragraphs 14.4.4 and 14.4.5, air-borne and ground-borne vibration effects are not considered further in this Stage 2 assessment.
Northern Route Corridor Options
North Corridor Option 1
14.4.7 North Corridor Option 1 is very similar to the present route corridor, making only one significant departure from the existing M90 mainline alignment for the proposed replacement bridge.
14.4.8 North Corridor Option 1 runs south from where the M90 crosses the B916. Southwards from this point, the M90 mainline widening remains contained within the present highway corridor until it reaches St Margaret’s Marsh. Significant earthwork alterations occur through Masterton Junction, just south of Fairy Kirk and through Castlandhill, west of Muckle Hill. At Ferrytoll Junction, the M90 mainline deviates west of the Forth Road Bridge alignment, taking it approximately 250m further to the west, to the eastern side of Queensferry Lodge Hotel.
14.4.9 As North Corridor Option 1 is largely an upgrading and widening of the existing route corridor, any noise impact is likely to be relatively small when compared with the Do-Minimum Option. The existing houses affected by the route corridor would receive a noise increase due largely to the predicted rise in traffic volume along the M90. Smaller increases in noise occur where the alignment is shifted slightly closer to residential and other noise sensitive properties, due to the widening.
14.4.10 One exception to this would be the proposed link road from Masterton Junction to the A921, just to the west of Inverkeithing High School. This new road would pass to the east of properties along the B981, becoming a major new noise source in this particular area. The east facing facades of these properties currently overlook open fields.
14.4.11 As with the do-minimum scenario, there are schools that would be within the vicinity of this route corridor: one (Inverkeithing High School) in the 0-50m band; one (Park Road Primary School) in the 50-100m band; and;three (Careshare Nursery, Inverkeithing Nursery and Inverkeithing Primary School) in the 300-400m band; and one (North Queensferry Primary School) in the 500-600m band.
14.4.12 The proposed road links at the Ferrytoll Junction are not close to residential areas and the construction works here would not be expected to give rise to significant effects. The carriageway alterations and cuttings works further north alongside Castlandhill are not estimated to exceed construction noise limit values although the noise increases relative to ambient noise levels would be estimated to be temporarily significant.
14.4.13 To the north of Rosyth, this route corridor option proposes a number of new links at the junction of the M90 and A823(M). There are no residential areas close enough here for there to be a likelihood of the noise limit values being exceeded. Also, given the relatively high ambient noise levels, the junction and structures works would not be expected to give rise to significant effects on the northeast edge of Rosyth. No further significant effects are expected north of the junction.
14.4.14 Around Masterton Junction, there would be Slight to Minor beneficial effects (-1 to >-5dB(A)). The new road from the A921 linking into the new junction at M90 would have a Slight Adverse effect (1-<3dB(A)) at North Road (B981) at those properties closest to road.
14.4.15 The results indicate a slight to Moderate Adverse effect of 3 to 10dB(A) along parts of the B980/B981 to Rosyth and the south link between Inverkeithing and the proposed replacement bridge.
14.4.16 St Margaret’s Hope to the west of the proposed replacement bridge would have a Moderate Adverse effect of 5-<10dB(A). The Queensferry Lodge Hotel noise effect changes from the east façade to west façade with an overall Major Adverse effect (>10dB(A)).
14.4.17 Properties in North Queensferry would be subject to Slight to Major Beneficial effects, i.e. -1 to <-10dB(A).
North Corridor Option 2
14.4.18 In comparison to North Corridor Option 1, North Corridor Option 2 makes significant departures from the existing M90 mainline alignment. North Corridor Option 2 begins where the M90 crosses the B916. However, soon after this point, the M90 mainline corridor diverts across to the east into deep cutting, whilst new slips take traffic back onto the existing M90 alignment to Masterton Junction. North Corridor Option 2 then rises back to level ground at Dales Steading / Dales Farm Cottage, before going onto high embankment down alongside the B981, until it crosses over the new Inverkeithing North Junction and the Edinburgh to Aberdeen and Fife Circle Railway lines. Properties along the B981 would have a clear line of sight to this new road due to its elevated position, with an associated noise.
14.4.19 At this point the road remains elevated on a section of bridge down to the A921 (Admiralty Road). Further embankment earthworks carry the M90 east of Inverkeithing, down to and over the existing A90, just south of Admiralty Junction and the B980.
14.4.20 At this point it drops below ground level into a cut and cover tunnel, just east of Castlandhill Farm Steadings, where it continues south towards Castlandhill Woods in shallow embankment. A new slip road feeds northbound traffic from the M90, across high embankment over and onto the existing A90. This embankment would provide beneficial screening of M90 traffic noise to Castlandhill Woods. North Corridor Option 2 would also relieve traffic noise currently impacting upon the cemetery south of Muckle Hill, by reducing traffic upon the existing A90. South of this point, the North Corridor Option 2 becomes the same as in North Corridor Option 1.
14.4.21 This route corridor option would relieve traffic along the existing A90 which would provide beneficial noise reductions for properties within the Admiralty Junction area. Whilst North Corridor Option 2 shifts traffic away from Admiralty Junction, because it is elevated, noise from this new road would not be as attenuated as if it were at grade level.
14.4.22 Properties in the northwest of Inverkeithing would be affected by the new elevated road source, and are likely to experience increased traffic noise.
14.4.23 The reduction in numbers of properties affected by North Corridor Option 2 compared with the current route is mainly due to the redirection of traffic away from the housing estate bounded by the M90 to the east, the A985 to the south and the A823(M) to the north.
14.4.24 North Corridor Option 2 would reduce the number of schools within the vicinity of the route to one (Park Road Primary School) in the 400-500m band.
14.4.25 North Corridor Option 2 proposes a new route alignment to the west of the A90 around the Castlandhill area; unlike North Corridor Option 1, temporarily significant effects are not expected here as the works would be more distant from noise sensitive receptors. North Corridor Option 2 would pass approximately 100m from the northwest edge of Inverkeithing and the cutting works here could give rise to temporarily significant effects. The section of new route corridor continuing north is not close to any residential locations and no significant effects are anticipated for the remainder of this route corridor option.
14.4.26 Although there could be some effects at Inverkeithing for North Option 2 , there would be less likelihood of noise effects at Muckle Hill and northeast Rosyth. Of the two northern route corridor options, North Corridor Option 2 is therefore considered marginally preferable in terms of construction noise.
14.4.27 The new road to the east of Masterton Junction would have Minor Adverse effects at some properties on Struan Place and Struan Drive (3-<5dB(A)) in Inverkeithing. Properties along the existing M90 and Park Road Primary School would be subject to a minor beneficial effect (-3 to >-5dB(A)). Properties along Castlandhill Road in Rosyth and Whinny Hill Crescent in Inverkeithing would be subject to a Moderate Beneficial effect (-5 to >-10dB(A)). Properties along Dunfermline Wynd/Hill Street in Inverkeithing would be subject to a major beneficial effect (<-10dB(A)).
14.4.28 Along the road connecting B980/B981 and Rosyth, there would be a Minor Adverse effect (3-<5dB(A)) at Castlandhill House.
14.4.29 St Margaret’s Hope to the west of the proposed replacement bridge would be subject to a Moderate Adverse effect (5-<10dB(A)). The Queensferry Lodge Hotel noise effect changes from the east façade to west façade with an overall Moderate Adverse effect (5-<10dB(A)).
14.4.30 Along the southern link between Inverkeithing and the bridge over the B981, there would be Moderate Adverse effects at properties (5-<10dB(A)). Some properties in North Queensferry would be subject to Slight to Major Beneficial effects, i.e. -1 to <-10dB(A).
Southern Route Corridor Options
South Corridor Option 1
14.4.31 Under South Corridor Option 1, the route corridor to the proposed replacement bridge remains broadly the same as the current alignmenr along the M9 spur until south of South Queensferry, where the road crosses Dolphington Burn, level with and west of the Royal Elizabeth Yard. At this point new slip roads join, taking traffic back to the existing northbound A90, whilst South Corridor Option 1 takes traffic further to the west before turning northbound, towards the proposed replacement bridge. This is the start of the new junction called Echline/Scotstoun Junction, which stretches from Dolphington Culvert to the east, to Dundas Home Farm and Ferry Muir to the west. The new slip roads join onto the A90 at Queens Crossing, whilst a smaller junction slightly west of this point feeds traffic to the A904 (Builyeon Road).
14.4.32 From here South Corridor Option 1 progresses west, past Echline Strip and the property White Lodge Dundas, before heading north, and going into cutting to take it under the A904/B924 ‘Y’ junction. From here it is supported by an embankment before joining onto the proposed replacement bridge, passing Inchgarvie House and other scattered properties within 300m on the western side.
14.4.33 There are three schools within the vicinity of South Corridor Option 1: one (Dalmeny Primary School) in the 100-200m band; one (Kirkliston Primary School) in the 300-400m band; and one (Echline Primary School) in the 400-500m band. There is also one (Leonard Cheshire Home) care home within the 300-400m band.
14.4.34 Widening or other alteration works on the M9 spur approximately 50m to the west of Kirkliston would involve some of the standard processes listed in Table 14.1. Calculations indicate that the worst-case daily noise levels for some of the phases would be estimated to be below 75dB(A) which is typically adopted by local authorities as the daily construction noise limit in urban areas. However, pavement and any piling operations would possibly be close to, or in exceedance of this limit, and therefore may require particular attention to mitigate this disturbance in accordance with best practicable means. Relative to the ambient noise levels which are dominated by the existing road traffic, the increase in noise level would be sufficient to be rated as a temporary significant effect if the works along this section continued over a period of two or more months.
14.4.35 Further north, South Corridor Option 1 would be aligned approximately 200-400m to the south of South Queensferry and the resulting noise levels would be well below the 75dB(A) limit value at residential properties here. As South Corridor Option 1 turns north along the west side of South Queensferry, it passes within approximately 150m of residential areas. Noise levels from the generic construction processes would still be less than the noise limit value (75dB(A)). The increase in noise level relative to ambient noise levels to the southwest and west of South Queensferry is estimated to be temporarily significant during the noisier phases given the likely duration of the works (i.e. assumed to raise noise levels by at least 3dB for longer than 8 weeks).
14.4.36 Along the B924, a number of properties and Echline Primary School would be exposed to a Minor Adverse effect (3—<5dB(A)). South Corridor Option 1, from the approach viaduct down to the A904, brings Major Adverse effects in noise to some residential properties at Inchgarvie House, Linn Mill, Cluflat Brae, Springfield Brae, Terrace and Crescent of >10dB(A).
14.4.37 On the north side of the A90 is the village of Dalmeny. Noise level changes in this area would be Negligible including those effects at Dalmeny Primary School. To the south is Dundas Home Farm that would be subject to increases of between 1 to <5dB(A), ie Slight to Minor Adverse. There are Moderate to Major Beneficial effects predicted in South Queensferry of between -5 to <-10dB(A) in the area around the existing bridge link road.
14.4.38 Kirkliston would be subject to Minor Beneficial effects (-3 to >-5dB(A)) in the northwest and western outskirts with no significant changes further into the centre of Kirkliston.
14.4.39 The relative benefits and disbenefits of the various route corridor options with respect to operational noise are compared in Section 14.6.
South Corridor Option 2
14.4.40 South Corridor Option 2 would comprise a new road branching off from the M9 via a new junction, between Humble Reservoir and Muiriehall Wood, directly to the proposed replacement bridge. There would also be a new eastbound slip road from the spur to A90 and a new slip road at M9 Junction 1A.
14.4.41 As the new road traverses northward, it passes between a number of isolated properties both to the east and west of the route corridor. To the east lie Dundas Castle and its grounds, including Castleloch Dundas and The Chalet Dundas, as well other isolated properties of Carmel Hill cottage, Dundas Mains, Rose-acre and Lilac Cottage, Brown-acre Dundas, Green-acre Dundas, Blue-acre Dundas and Chapel-acre Dundas. Other properties to the west of South Corridor Option 2 include Swineburn, Totleywells Grange, Westfield, Holly Cottage, Baroncraig, Gillerhill and Lawflat Duddingston. All these areas would be subject to a noise increase due to the locality of the new road, although this would be mitigated to a certain degree as the new road would be in cutting along most of its length.
14.4.42 The potential noise increases that the closest properties would be exposed to for South Corridor Option 2, would be more severe than for South Corridor Option 1, due to the low ambient noise climate in this very rural area. The topography in this area is fairly undulating and complex, and would therefore have a significant bearing on the potential for noise impact that the new road could have on the various scattered properties in this area.
14.4.43 Under this route corridor option, traffic along the M9 spur would be significantly reduced, providing noise reductions to properties along this existing section of road.
14.4.44 There are three schools within the vicinity of South Corridor Option 2: one (Dalmeny Primary School) in the 50-100m band; and two (Echline Primary School and Kirkliston Primary School) in the 300-400m band. There is also one (Leonard Cheshire Home) care home within the 300-400m band.
14.4.45 The construction noise effects to the west of Kirkliston would be the same as those described above for South Corridor Option 1. Alterations associated with South Corridor Option 2 at the Scotstoun Junction would bring the works close to Dalmeny, but it is not expected that the noise levels would be high enough to exceed the 75dB(A) limit here according to the construction noise prediction approach set out in Section 14.2 (Approach and Methods). This corridor option incorporates a new section of highway from the M9 northeast to the west of South Queensferry. This would pass through a relatively unpopulated area. The closest residential property to this route corridor is Westfield Farm approximately midway between the M9 and the A904. However, this property would not be expected to receive construction noise levels in excess of the limit value. The construction noise effects would be expected to be rated as temporarily significant, however, given the ambient noise levels and the likely duration of the excavation works for the cutting here (i.e. assumed to raise noise levels by at least 3dB for longer than 8 weeks).
14.4.46 Further north, the effects to the west side of South Queensferry would be as described above for South Corridor Option 1, i.e. estimated to be temporarily significant relative to ambient noise levels.
14.4.47 Compared to South Corridor Option 1, South Corridor Option 2 is likely to result in less construction noise effects as there would be less new highway works to the south of South Queensferry.
14.4.48 From the proposed replacement bridge south towards the A904, residential properties at Inchgarvie House, Linn Mill, Cluflat Brae, Springfield Brae, Terrace and Crescent would experience Major Adverse effects (>10dB(A)).
14.4.49 There is very little change in noise at properties along Builyeon Road (A904) closest to the South Corridor Option 2, but properties further along this road to the east would be subject to a noise reduction of between 2-<3dB(A), i.e. onset of Significant Beneficial effect.
14.4.50 White Lodge Dundas at Westfield, Totleywells Grange, Baroncraig and Holly Cottage would be subject to a Major Adverse effect (>10dB(A)). Moderate Adverse effects (5 to <10dB(A)) are predicted at Dundas Castle, Dundas Mains and Swineburn.
14.4.51 Properties at Dundas Home Farm and Newbigging would be subject to a Moderate Beneficial effect (-5 to >-10dB(A)). There are Moderate to Major Beneficial effects predicted in South Queensferry of between -5 to <-10dB(A) in the area around the existing bridge link road.
14.4.52 Kirkliston would have Minor Beneficial effects (-3 to >-5dB(A)) in the northern outskirts, with a Moderate Beneficial effect (-5 to >-10dB(A)) in the southeast outskirts. There is predicted Insignificant to onset of Significant Beneficial effect toward the centre of Kirkliston.
14.5 Potential Mitigation
14.5.1 At DMRB Stage 2 assessment of route corridor options, the detailed design has not been developed, and mitigation detail therefore cannot be accurately defined. The objective of this section is therefore to identify ‘standard’ or ‘anticipated’ mitigation taking into account best practice, legislation and guidance. This mitigation is taken into account in the subsequent identification of likely residual impacts in Section 14.6 (Summary of Route Corridor Options Assessment), to provide a robust basis for comparative assessment and selection of a preferred route corridor option to be taken forward to Stage 3.
14.5.2 Proposals for the mitigation of construction and operational noise are described in the following section. An estimate has been made of the approximate lengths of screening required for each route corridor option based on the locations alongside the route corridor options where significant effects have been identified.
Construction Noise and Vibration
14.5.3 The potential noise and vibration effects of the construction works would be addressed to reduce disturbance at all stages of the work. Working with the best practice guidance, opportunities would be sought to minimise the level and duration of noise exposure from construction according to established best practicable means. It is also intended that local residents should be kept informed of the possibility of disturbance and information made available regarding the nature and duration of the works likely to affect them. The measures taken to control potential disturbance would also be described as part of the public liaison exercise.
14.5.4 For all of the construction processes, all reasonable measures would be taken to minimise noise impact during these operations to protect residential properties and other noise sensitive areas from excessive noise exposure. This would be achieved using best practicable means according to measures described in BS 5228. In the case of the potential for vibration effects, reference would also be made to BS 6472 and BS 7385-2 which contain advice on the evaluation and measurement of vibration.
14.5.5 Those areas where temporary significant effects were identified for the construction works would receive particular attention to minimise noise effects. Similarly, areas where there is the potential for noise levels to exceed the 75dB(A) daily noise limit generally adopted for construction work would also be considered for mitigation to keep noise below this limit.
14.5.6 Locations closest to the Forth Replacement Crossing would be subject to the highest construction noise levels although many of these may also benefit from screening as part of the traffic noise mitigation plan. It is proposed that, where practicable, these screening measures should be installed before the construction works which would reduce the construction noise levels considerably.
14.5.7 The Contractor would liaise with the relevant Local Authorities for each area and specific local requirements would be agreed regarding working hours and prohibited activities. Specific noise control practices could be written into prior consents set out under Section 61 agreements (Control of Pollution Act) between the Contractor and the Local Authority. Concessions might be negotiated for exceptional specific activities such as working outside of standard hours.
14.5.8 The Contractor would work with the local authorities to ensure local policy requirements are addressed and to satisfy the local authorities that construction noise and vibration effects are minimised. The likely requirements will be identified during consultation as part of Stage 3 assessment.
14.5.9 General measures would include the selection of appropriate plant, construction methods and programming. Plant would be required to conform to the relevant national or international standards on noise emission (refer to British Standard 5228). If practicable, dedicated acoustic screening would be used in optimal positions if considered to be of particular benefit.
14.5.10 Strict adherence to working time limits would be operated to ensure that any noise disturbance is only likely to occur within agreed hours, unless exceptional working has been agreed in advance with the relevant local authority.
14.5.11 Monitoring of noise levels may be required during the construction works to ensure that any action levels agreed between the Contractor and the local authority are not exceeded at established monitoring positions.
14.5.12 Where piling is necessary, non-impactive piling would be used at positions closest to noise sensitive properties if it is possible to do so. The choice of piling technique would be reviewed once the construction programme is finalised.
14.5.13 Plant machinery such as generators or compressors would be positioned as far from noise sensitive locations as possible and ideally in naturally screened positions. All plant equipment would be adequately maintained to minimise noise emission. HGV traffic delivering and removing materials or plant to and from the site would access the works area via the most suitable route corridor.
14.5.14 The significance criteria adopted for the purposes of this study have been described above in terms of the degree of traffic noise increase likely to cause significant effects. For the Forth Replacement Crossing, the use of mitigation would be considered, where practicable, at residential locations identified as being subject to significant effects (i.e. increases of 3dB or more). Figures 14.1 and 14.9 provide noise bands based on available traffic data, and indicate areas where noise levels may increase by 3dB or more and hence mitigation (such as noise barriers or false cuttings) may be appropriate.
14.5.15 The Stage 2 DMRB methodology requires that those options requiring ‘particularly extensive mitigation’ are identified.
14.5.16 Mitigation requirements have been based on the noise mitigation criteria defined earlier in the chapter, i.e. those residential areas where noise increases are 3dB or more, or that meet the criteria of the Noise Insulation (Scotland) Regulations. These estimates of mitigation requirement are based solely on areas meeting the criteria above with no consideration (at this stage) of other factors such as landscaping. The requirement for mitigation is based on the noise map predictions that take into account topography and actual traffic flow information, as this is considered to be more accurate than only using the separation distance between source and receptor (Table 14.3). The northern route corridor option requiring the most mitigation would be North Corridor Option 2 (potentially just over 1km of screening), although the requirement for North Corridor Option 1 would be only marginally less (potentially 1km of screening). The southern route corridor option requiring most mitigation would be South Corridor Option 2 (potentially 5km of screening), as compared with South Corridor Option 1 (potentially 3km of screening).
Residual Impacts & Effects
14.5.17 The mitigation measures described above to control construction noise effects would ensure that disturbance from construction activities would be reduced at sensitive locations. Also, residents would be kept informed of the likely nature and duration of any disturbance in their area.
14.5.18 A detailed noise mitigation plan has not been made as part of this Stage 2 assessment, hence it is not possible to precisely assess the residual effects. However, it can be assumed that in most locations, significant effects would be prevented. In some locations subject to large noise increases, the effects would be diminished although effects may still be rated as significant. It is also considered that the mitigation plan would be effective at reducing noise levels below 68dB(A) (NIR threshold) at most locations.
14.5.19 It should be noted that a detailed mitigation plan would be developed as part of the Stage 3 assessment.
Cumulative Impacts & Effects
14.5.20 The noise effects reported as part of this study of the Forth Replacement Crossing route corridor options could be potentially affected by other new noise sources within the study corridor that could not be considered as part of this assessment. For example this might include nearby highway alterations for other road schemes, airfields, industrial installations, or construction of buildings that could provide additional screening from the road. On the basis of information available at the time of this assessment, there appear to be no such major noise sources or construction projects which are of a scale that would be identified as having a cumulative noise effect when combined with the Forth Replacement Crossing.
14.5.21 Schemes that may be under construction at the same time as Forth Replacement Crossing are identified in Chapter 18 (Policies and Plans). The scheme known at this time as of potential relevance in the vicinity of the Forth Replacement Crossing is the anticipated redevelopment at Port Edgar on the southern side of the Firth of Forth, although this is likely to be of a relatively small scale.
14.5.22 It is possible, of course, that there would be proposals which are yet to be registered in the planning system that could result in localised noise effects due to the introduction of a new noise source or a screening structure.
14.6 Summary of Route Corridor Options Assessment
14.6.1 Noise and vibration effects have been considered for the construction works and the operation of the Forth Replacement Crossing. The range of construction noise levels has been approximated based on typical highway construction processes. The operational noise levels have been estimated using the appropriate noise prediction methodologies. The operational assessment has compared the ambient noise levels before opening (2017), against the design year noise levels (2032).
14.6.2 Comparing the construction noise effects estimated for the different route corridor options, it is considered that South Corridor Option 2 and North Corridor Option 2 would be marginally preferable to the alternatives with respect to construction noise effects.
14.6.3 For all of the construction processes, all reasonable measures would be taken to reduce noise impact during these operations to protect residential properties and other noise sensitive areas from excessive noise exposure. This would be achieved using best practicable means according to the relevant guidance. Those areas where significant effects have been estimated, or noise limits are likely to be exceeded, would be subject to particular attention.
14.6.4 Mitigation requirements have been based on the noise mitigation criteria defined earlier in the chapter, i.e. those residential areas where noise increases are 3dB or more, or that meet the criteria of the Noise Insulation (Scotland) Regulations.
Northern Route Corridor Options
14.6.5 North Corridor Option 2 would give rise to significant benefits northeast of Rosyth although there would be some significant adverse effects on the northwest edge of Inverkeithing. It would be expected that the noise increases could be mitigated to lessen the adverse effects. North Corridor Option 1 would give rise to very few adverse effects in residential areas although the noise benefits at Rosyth would be smaller.
14.6.6 Comparing the northern route corridor options, the overall balance of positive and negative noise effects is marginal. However, it may be considered preferable to avoid the potential for adverse effects at the northwest of Inverkeithing (despite the significant benefits elsewhere), in which case North Corridor Option 1 would be rated as preferable.
Southern Route Corridor Options
14.6.7 From the assessment of operational noise effects associated with the southern route corridor options, it is considered that South Corridor Option 2 is favourable in terms of overall noise effects. This is due to the diversion of traffic away from the A90 south of South Queensferry which would result in significant noise reductions to a large number of properties in this area. Conversely, the South Corridor Option 2 between the M9 and the A904 would result in large noise increases affecting a small number of rural properties. South Corridor Option 1 does not afford the same degree of noise reduction in South Queensferry, although the rural areas to the southwest of South Queensferry would remain unaffected.
14.6.8 On balance, South Corridor Option 2 is considered to have lower overall noise effects.
14.7 Scope of Stage 3 Assessment
14.7.1 The Stage 3 assessment will build upon the Stage 2 assessment but will use the latest version of DMRB published in August 2008 (The Highways Agency et al., 2008) and will include the following tasks:
- A baseline noise survey to establish ambient noise levels, particularly in areas not currently dominated by road traffic noise, where predicted baseline traffic noise levels may be less reliable.
- Dwelling façade noise calculations to 600m either side of the alignment for Do-Minimum and Do-Something conditions in the baseline and future years (2017 and 2032) will be undertaken; dwellings will be classified in 3dB noise exposure bands between 47.5 and 83.5dB(A). Tables will be produced showing the results of property counts in different noise change bands occurring between the following scenarios:
a) Do-Minimum 2017 vs Do-Minimum 2032.
b) Do-Minimum 2017 vs Do-Something 2032.
- A qualitative assessment for dwellings and other sensitive receptors located between 600-2000m from the route.
- A simple assessment of the affected route (i.e 1dB change in opening year) within the study area that are outside the noise calculation area for Do-Minimum and Do-Something in 2017 and 2032.
- An assessment of the number of dwellings and other noise sensitive dwellings affected by temporary impacts will be made. Construction operations that may have a significant impact will be identified and appropriate mitigation proposed.
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