12 traffic & transportation
TRANSCRIPT
Glyn Rhonwy Pumped StorageDevelopment Consent Order
6.02 Environmental StatementVolume 2
October 2015
12.1 Introduction ................................................................................................... 112.2 Scope of Assessment ................................................................................... 212.3 Legislation and Policy Framework .............................................................. 412.4 Consultation .................................................................................................. 412.5 Methodology .................................................................................................. 612.6 Baseline Conditions .................................................................................... 1412.7 Traffic Data .................................................................................................. 2912.8 Potential Effects .......................................................................................... 3312.9 Mitigation, Compensation and Enhancement Measures ......................... 6112.10 Residual Effects ........................................................................................ 6412.11 Evaluation of Significance ....................................................................... 6412.12 Summary and Conclusions ..................................................................... 6712.13 References ................................................................................................ 68
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12.1 Introduction
12.1.1 This chapter will set out the potential highway effect during the construction,
operational and decommissioning phases of the Development. The
proposed scope has been discussed and agreed with the Local Highway
Authority.
12.1.2 The methodology is in line with the Institute of Environmental Management
and Assessment’s (IEMA) ‘Guidelines for the Environmental Assessment of
Road Traffic’ (January 1993) and the ‘Guidance on Transport Assessment’
(DfT, March 2007). It has also been agreed with Gwynedd Council through
the 2012 ES for the approved scheme and has been repeated for comment
in the Scoping Report submitted on the 5th January 2015 for the
Development.
12.1.3 It should also be noted that the proposed construction traffic flows used to
assess the percentage impact have been increased by 25% from those
given in the Construction Trip Generation tables in order to provide a level
of robustness to the assessments given in this report.
Summary of 2012 Environmental Statement Chapter
12.1.4 The most significant effect of the Development will be during the
construction phase, which will last for approximately 4 years with daily
vehicle movements varying according to the construction operation being
undertaken. Key effects are an increase in traffic volume on the surrounding
network, including Heavy Goods Vehicles (HGVs) with the main issues of
concern relating to access to the site from the east around Llanberis and
from the west around Croesywaun / Waunfawr.
12.1.5 Highway improvements are required on the unclassified road (known as
Green Road) from Waunfawr to Q1 (detailed in Section 12.9). These are
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not proposed to form part of this DCO application but will instead be dealt
with using a Section 278 Agreement with the Local Highway Authority and
be subject to its own planning application.
12.1.6 Once operational, the Development will be manned by approximately 25-35
staff during normal operation. This assessment is based on an assumption
of staff working on a 3-shift system.
12.1.7 Therefore the majority of traffic effects are assumed to be in the
construction phase, which will be temporary in nature.
12.1.8 Impacts will be mitigated through the implementation of a Construction
Traffic Management Plan (CTMP) and Health and Safety Plan (HASP).
These mitigation measures will reduce the potential residual traffic effects
from the construction and operation of the approved scheme, and therefore
the effects are considered to be not significant.
Scope of 2015 Environmental Statement Chapter
12.1.9 This chapter has been updated as follows:
Updated planning policy (Section 12.3);
Updated baseline conditions (Section 12.6);
Updated traffic data information (Section 12.7);
Updated potential effects (Section 12.8);
Updated residual effects (Section 12.10); and
Updated evaluation of significance (Section 12.11).
12.1.10 The updated Construction Traffic Management Plan for the Development
can be found in Volume 3, Appendix 16.1.3 as this is part of the CoCP.
12.2 Scope of Assessment
12.2.1 Discussions have been undertaken regarding the potential effect of the
Development with the Local Highway Authority; Gwynedd Council. Given
the requirement for two points of access into the site, one from the west and
one from the east, the following junctions have been identified as requiring
consideration:
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A4244 / A4086 priority junction;
A4086 / Glyn Rhonwy priority junction;
A4086 / unnamed road priority junction within the settlement of Pont-
Rug;
A4085 / unnamed road roundabout junction within Caeathro;
A4085 / unnamed road priority junction to the north of Croesywaun, and
Priority crossroads to the north west of Croesywaun.
12.2.2 Traffic counts were undertaken on Thursday 26th March 2015 between
07:00-19:00 hrs to establish not only the peak hour traffic data, but also the
daily traffic flow, which is more relevant to the construction period where
vehicles will be arriving and departing throughout the working day.
12.2.3 The above data provides the base traffic levels at the key routes to the site
from both the west and east.
12.2.4 The traffic for the construction effect has been based upon the construction
methodology and information provided relating to numbers of workers on
site and types, sizes and numbers of any larger abnormal loads to the site.
12.2.5 Based on the above, the construction traffic to both Q1 and Q6 of the
Development has been quantified and assessed against base traffic levels,
with the swept path of all critical vehicle types also being checked. From
this analysis it can be demonstrated that all movements can be
accommodated in a safe and efficient manner.
12.2.6 It should be noted that once operational, the access would be from the
A4086 with occasional planned maintenance trips to the Q1 headpond on
the Waunfawr side. Access routes for both construction and operational
phases are shown in Volume 4, Figure 4.16.
12.2.7 The operational phase has been quantified based on the staffing
requirements as well as the maintenance regime, which requires larger
vehicles to access Q6 tailpond.
12.2.8 In relation to decommissioning, the water would be drained from the
quarries to Llyn Padarn and above ground building structures removed. The
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penstock, tailrace and spillway infrastructure will remain although the
pumping station will be dismantled. Given the minimal traffic and lack of
abnormal loads required, it is considered to have a negligible effect and so
is not considered further. This was agreed to be scoped out in the 2012 ES.
12.2.9 The accident records for the surrounding local highway network have been
requested from Gwynedd Council and this has been reviewed to ascertain
whether there are any areas of concern on the local highway network that
may be exacerbated by the Development.
12.3 Legislation and Policy Framework
National Planning Statements
12.3.1 The following National Policy Statements (NPS) for Energy are relevant to
this chapter for the Development: EN-1 (Overarching Energy), Section 5.13.
It identifies where there is a need for a Transport Assessment (TA) and a
Travel Plan (TP).
Planning Policy Wales (7th Edition, July 2014)
12.3.2 The Development has been assessed against the relevant policies, which
relate to this site. The policy has a strong regard and focus on accessibility
and extending modal choice.
12.3.3 The policy sets out a transport hierarchy with walking and cycling being the
preferred mode of choice, followed by public transport and then the private
motor vehicle.
Technical Advice Note 18: Transport
12.3.4 TAN 18 should be read in conjunction with Planning Policy Wales and
provides further information regarding the policies to be considered when
bringing forward development.
12.4 Consultation
12.4.1 Discussions were undertaken with officers of Gwynedd Council in 2012 for
the approved scheme and in 2015 for the Development, the details of these
discussions are set out in Table 12-1.
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Table 12-1 Summary of Consultation/Discussion UndertakenDate Summary of Comments/DiscussionsTelephoneDiscussion23rd May2012
AECOM spoke to the Highways Department of GwyneddCouncil regarding the principle of the Development and toascertain initial thoughts regarding the routing of constructiontraffic, mindful that construction traffic would lead to thegreatest effect on the road network.AECOM were advised that all construction traffic shouldaccess the site from the A4086 using the A4244 to access thewider network on the A55 rather than travel throughCaernarfon.
E-Mail 23rd
May 2012AECOM issued a proposed list of junctions to be subject totraffic counts during the weekday AM and PM peak hourperiods to ascertain the base traffic levels on the highwaynetwork.
E-mails29th May2012
Following a site visit by AECOM, the junctions to be subject totraffic counts were slightly amended to include the routebetween the A4085 and A4086. A confirmation e-mail wassent to Gwynedd Council Highways to obtain agreement.The scope of traffic surveys was then further refined in atelephone discussion where it was requested that 12-hourturning counts be undertaken at six junctions on the localhighway network, with an agreement that they could beundertaken in week commencing 13th June 2012.
Meeting29th June2012
On 29th June 2012, AECOM met with Gwynedd CouncilHighways to discuss the approved scheme and to issue a setof drawings showing the vehicular swept paths of constructionvehicles accessing both sides of the site.At the meeting AECOM set out the potential effect upon theminor road from Waunfawr up to the quarry and highlightedthe requirement for passing places to allow HGVs and othervehicles to pass, given the existing road width ofapproximately 2.5 metres.AECOM also raised the potential effect upon on-street parkingat the crossroads within Waunfawr and the potential need toprovide a new car park to reduce the conflict with any HGVsthat will be visiting the site.The local authority also raised the issue that during periods ofsnow and ice, the access road to the quarry from Waunfawr isusually closed and that access will be extremely difficult.AECOM issued the swept path drawings showing thefollowing vehicles are be able to access the site:
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Table 12-1 Summary of Consultation/Discussion UndertakenDate Summary of Comments/Discussions
• Low Loader with a Moxy MT36;• Low Loader with a JCB JS360;• Low Loader with a CAT D6N Dozer, and• 400T Mobile Crane.
The conclusion of the swept path analysis being that basedupon the available OS data, the vehicles could beaccommodated on the local highway network from the A4085through the crossroads at Waunfawr. However, once onto theminor access road some localised widening would berequired.
Meeting26 March2015
On 26 March 2015, AECOM met with Gwynedd CouncilHighways in order to discuss the Development and conditionsurvey.At the meeting AECOM agreed the scope of the conditionsurvey and agreed the scope of the carriagewayreinstatement following construction of works.AECOM confirmed that a topographical survey had beencarried out and that previously undertaken track analysis willbe updated onto the survey.
12.4.2 A site visit and additional consultation was undertaken with Colletts to
determine the potential for haulage vehicles to ascend Green Road in order
to gain access to the Q1 site. The access road was driven twice, with
scheduled stops at the proposed passing places and also at proposed
localised widening and straightening locations.
12.4.3 It was discussed that traffic management would need to be designed and
implemented along the length of the Q1 access road. Even with the
introduction of passing places, it was discussed that vehicles travelling
uphill would struggle to continue uphill if forced to wait for a vehicle
approaching in the opposite direction.
12.5 Methodology
12.5.1 This section details the methodology adopted within the assessment of the
traffic and transportation element of the Development, and it should again
be restated that the traffic numbers used to assess the percentage impact
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have been increased by 25% from those given in the Construction Trip
Generation tables in order to provide a level of robustness to any
assessment.
12.5.2 The trip generation for both the construction and operational phase of the
Development was based on a first principles approach taken from
information provided for both the construction methodology and size and
type of vehicles required. In addition, the final number of employees at the
site and the type of vehicles required as part of any ongoing maintenance of
the quarry sites was also used for the adopted approach.
12.5.3 Trips were assigned to the local highway network and assessed against the
base traffic levels taken from traffic surveys at key junctions, as agreed with
Gwynedd Council.
12.5.4 The traffic effect from the Development was then quantified, and if it was
considered to have a material effect, capacity analysis was undertaken with
suitable mitigation provided (if required).
12.5.5 Given the nature and type of vehicles required as part of the construction
phase, swept path analysis was undertaken at key points on the network to
ensure that all required vehicle types could safely access the site, with
suitable mitigation provided as required.
12.5.6 The IEMA guidelines report is the only document available that sets out a
methodology for assessing potentially significant environmental effects
where a development is likely to give rise to changes in traffic flows. The
IEMA guidelines suggest that to determine the scale and extent of the
assessment and the level of effect which a given development will have on
the surrounding road network, the following two ‘rules’ should be followed:
Include highway links where traffic flows are predicted to increase by
more than 30% (or where the number of HGVs is predicted to increase
by more than 30%).
Include any other specifically sensitive areas where traffic flows are
predicted to increase by 10% or more.
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12.5.7 The significance of each effect is considered against the criteria within the
IEMA guidelines, where possible. However, the IEMA guidelines state that:
‘For many effects there are no simple rules or formulae which define the
thresholds of significance and there is, therefore, a need for interpretation
and judgement on the part of the assessor, backed-up by data or quantified
information wherever possible. Such judgements will include the
assessment of the numbers of people experiencing a change in
environmental impact as well as the assessment of the damage to various
natural resources.’
12.5.8 In the absence of established significance criteria for traffic and transport
effects, professional judgement has been used to assess whether the
effects on traffic and transport are considered to be significant. This is
carried out using the IEMA guidelines to identify the scale and extent of the
assessment to be undertaken. The significance falls into two categories -
not significant and significant. The latter corresponding to significant effects
in accordance with the EIA regulations.
12.5.9 The IEMA guidelines state projected changes in traffic of less than 10%
creates no discernible environmental effect, given that daily variations in
background traffic flow may fluctuate by this amount, and that a 30%
change in traffic flow represents a reasonable threshold for including a
highway link within the assessment. The threshold for a detailed
assessment has therefore been set at a 30% change in traffic flow.
12.5.10 The existing baseline conditions and the Development are set out in Section
12.6. The potential effects on baseline conditions and geographical
receptors arising from the Development are then identified and a magnitude
of scale of effect determined.
12.5.11 The general methodology of this process can be summarised as follows:
Set out baseline conditions;
Identify effect by type in relation to traffic flow and infrastructure;
Consider effect severity in confidence level;
Consider mitigation; and
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Identify residual effect remaining.
12.5.12 The definition of type and scale of effect can then be given as follows in
Table 12-2.
12.5.13 The importance of severity of any identified environmental receptor has
been scaled depending on its relative importance as set out in Table 12-3.
The receptors of the effects are defined geographically.
12.5.14 Based upon the above, the following significance matrix identifies the
significance of each effect, as shown in Table 12-4.
12.5.15 The level of confidence on which the predicted effects are assessed is
outlined in Table 12-5.
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Table 12-2 Definition of Type and Scale of Effect
Effect Description Development Receptors
Substantial Construction Significant number of construction vehicles using roads for a protracted period of time
Public Transport Users No provision for access by public transport
Pedestrians / Cyclists No facilities for pedestrians and cyclists or linkages to local facilities
HGVs Over a 41% increase in vehicle trips
Traffic Flows Over a 41% increase in vehicle trips
Road safety Significant increase in traffic at known accident locations
High Construction High number of construction vehicles using roads over a protracted period of time
Public Transport Users Limited provision for access by public transport
Pedestrians / Cyclists Limited facilities for pedestrians and cyclists with limited crossing facilities and lowquality linkages to the local facilities
HGVs Between 31% to 40% in vehicle trips
Traffic Flows Between 31% to 40% in vehicle trips
Road safety High increase in traffic at known accident locations
Moderate Construction Moderate number of construction vehicles using roads over a protracted time period
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Table 12-2 Definition of Type and Scale of Effect
Effect Description Development Receptors
Public Transport Users Few provisions for access by public transport
Pedestrians / Cyclists Few facilities for pedestrians and cyclists with limited crossing facilities and linkages tothe local facilities
HGVs Between 16% and 30% increase in vehicle trips
Traffic Flows Between 16% and 30% increase in vehicle trips
Road safety Moderate increase in traffic at known accident location
Minor Construction Small number of construction vehicles using roads over a short period of time
Public Transport Users Some provision for access by public transport
Pedestrians / Cyclists Facilities for pedestrians and cyclists with safe and convenient crossing facilities andgood linkages to the local facilities
HGVs Between 6% and 15% increase in vehicle trips
Traffic Flows Between 6% and 15% increase in vehicle trips
Road safety Minor increase in traffic at known accident locations
Negligible Construction Occasional construction vehicles using roads over a short period of time
Public Transport Users Some provision for access by public transport
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Table 12-2 Definition of Type and Scale of Effect
Effect Description Development Receptors
Pedestrians / Cyclists Dedicated facilities for pedestrians and cyclists with safe and convenient crossingfacilities and good linkages to the local facilities
HGVs Less than a 5% increase in vehicle trips
Traffic Flows Less than a 5% increase in vehicle trips
Road Safety Negligible increase in traffic at known accident locations
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Table 12-4 Significance of Effect
Scale International National Regional County Local
Effe
cts
Substantial Substantial Substantial Substantial High Moderate
High Substantial Substantial High Moderate Minor
Moderate Substantial High High Moderate Minor
Minor Moderate Moderate Moderate Minor Minor
Negligible Negligible Negligible Negligible Negligible Negligible
Table 12-5 Effect Prediction Confidence
ConfidenceLevel Description
HighThe predicted effect is either certain i.e. a direct effect, orbelieved to be very likely to occur, based on reliable informationor previous experience.
Low
The predicted effect and its levels are best estimates, generallyderived from first principles of relevant theory and experience ofthe assessor. More information may be needed to improveconfidence levels.
Table 12-3 Importance of Receptor
Designation Development Receptors
International European Community
National UK
Regional North Wales
County Gwynedd Council
Local Waunfawr and Llanberis
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12.6 Baseline Conditions
12.6.1 This chapter will outline the operation of the local highway network and will
cover the following issues:
Highway Network;
Traffic Data;
Public Transport, and
Road Safety.
Highway Network
12.6.2 AECOM visited the local highway network to observe existing traffic
conditions and to measure any critical highway dimensions and outline our
findings as follows.
Wider Highway Network
12.6.3 The access to the local highway network would be gained via the A55 to the
north and whilst the exact route beyond this is yet to be determined, the
A55 is a high quality route which gives access to the wider network. This
route is therefore considered to be able to accommodate the construction
traffic and as such no further consideration is required.
12.6.4 The route to the more local network around the A4086 would be gained via
junction 11 of the A55, which is a grade separated roundabout, with the A55
passing underneath the junction. Traffic would then travel along a short
length of the A5 before joining the A4244 at an at-grade roundabout.
12.6.5 Access to the western part of the Development would be via junction 9 of
the A55, from which vehicles would travel along the A487 to Caernarfon
before turning onto the A4085.
A4244 / A4086 Junction
12.6.6 For the eastern portion of the Development, vehicles follow the A4244 from
the A55 (as indicated above) then travel south to a right turn ghost island
junction with the A4086, from where vehicles would then turn right to
access the eastern side of the site via the A4086.
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12.6.7 The junction of the A4244 and A4086 is a right turn ghost island, with the
A4244 flaring to form a short two lane approach to the junction as shown on
the photographs below.
Photograph 1 A4244 /A4086 priority junction
Photograph 2 A4244approach
12.6.8 The junction incorporates street lighting and is considered to provide a high
quality access to the A4086. At the time of our site visit the junction
operated well within capacity with no queuing or delay.
A4085 / Glyn Rhonwy Junction
12.6.9 The A4086 then continues south to form a right turn ghost island with Glyn
Rhonwy just to the west of Llanberis, with Glyn Rhonwy forming the route
into the eastern side of the site.
12.6.10 At the junction with Glyn Rhonwy, the A4086 is 9.7m in width with through
lanes in both directions of 3m and a right turning lane of 3.7m width. Glyn
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Rhonwy flares at the junction, but does reduce to a width of 6.3m. The
layout of the junction can be shown on the following photographs.
Photograph 3 A4086 /Glyn Rhonwy junction
Photograph 4 GlynRhonwy approach tothe junction
12.6.11 At the time of our site visit the junction operated well within capacity with no
queuing or delay and the A4086 was lightly trafficked throughout our
observations.
Access to the Eastern side of the Quarry
Glyn Rhonwy
12.6.12 Glyn Rhonwy provides an access to the Siemens headquarters building and
approximately 100m from the junction with the A4086 a side road provides
access to an area of industrial development, whilst this has not currently
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been developed the full highway infrastructure has been provided, although
at the time of our visit this was gated to prevent vehicular access.
12.6.13 Glyn Rhonwy has a footway along the western side only with street lighting
and at the time of our visit both Glyn Rhonwy and the A4086 were relatively
lightly trafficked.
12.6.14 The existing junction with Glyn Rhonwy is a simple priority junction as
shown on the photographs below.
Photograph 5Industrial accessroad junction withGlyn Rhonwy
Photograph 6Industrial accessroad junction withGlyn Rhonwy
12.6.15 The above junction then provides an access onto the local highway network
from the site.
Existing Industrial Access Road
12.6.16 The industrial estate road is 6.2m in width and has a footway along one side
with street lighting along the main spine road through the site, a stub
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access road has been provided into numerous areas, although as outlined
previously, no development has taken place.
12.6.17 The road provides a route through the future development site to Ffordd
Clegir which provides a route through Llanberis to the edge of the quarry
site, although this junction has been closed off as shown on the
photographs below.
12.6.18 The route to the edge of the quarry forms a side road with the spine road
from Glyn Rhonwy and has a loose surfaced footway along both sides for
part of the route, but no street lighting. There is also a section of road where
no footway has been provided as it passes over a development area that
has been set at a lower level.
12.6.19 The industrial estate road and route to Q6 can be shown on the following
photographs.
Photograph 7Industrial access roadjunction with GlynRhonwy
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Photograph 8Industrial access roadthrough the site
Photograph 9 Accessroad to the quarry
Photograph 10 Accessroad to the quarryshowing the raisedsection
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Photograph 11 Accessroad to the quarryjunction with FforddClegir
12.6.20 This route therefore provides a high quality access from the eastern edge of
the site to the main A4086 via Glyn Rhonwy.
Ffordd Clegir
12.6.21 As mentioned above Ffordd Clegir provides a route to the quarry from
Llanberis and varies in width from 2.5m to 4.5m and passes through
Llanberis town centre where there are residential properties and on-street
parking which restricts the road width. The route can be seen on the
following photographs.
Photograph 12 FforddClegir
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Photograph 13 FforddClegir throughLlanberis
12.6.22 Given the road width and route through Llanberis it would be considered
that the preferred route to the quarry on the eastern side would be from the
A4086 and Glyn Rhonwy to gain access through the future development
land.
Access to the Western Side of the Quarry
12.6.23 To access the western side of the quarry, as outlined previously, vehicles
would turn onto the A487 from the A55, then onto the A4085 in Caernarfon.
12.6.24 Vehicles travel along the A4085 to access the quarry from an unnamed
road to the north of Croesywaun.
12.6.25 The village of Croesywaun provides three potential routes to the access
track into the quarry, with each requiring vehicles to travel through the
crossroads junction at Cae Trefor; these can be examined further as
follows.
Option 1 – Junction to the north of Croesywaun
12.6.26 This is a simple priority junction with the A4085 having a width of 6.2m and
the side road to the quarry having a width of 4.8m. The layout is shown on
the following photographs and as can be seen, there is a pinch pint of width
4.8m due to the location of the building at the boundary of the highway.
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Photograph 14Unnamed side road tothe north ofCroesywaun
Photograph 15Unnamed side road tothe north ofCroesywaun –visibility to the left
Photograph 16Unnamed side road tothe north ofCroesywaun –visibility to the right
12.6.27 The side road then continues along a straight alignment to the crossroads
at Cae Trefor, where vehicles accessing the quarry would be able to make
a straight ahead movement.
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12.6.28 Given the alignment of the unnamed road and the fact that vehicles can
travel straight ahead the crossroads, this would be considered to be the
preferred means of access into the quarry from the west, albeit that there
are issues regarding visibility, road width and alignment to be addressed.
These are discussed later within this chapter.
Option 2 – Junction with Pant Y Waun the centre Croesywaun.
12.6.29 This forms a simple priority junction with the A4085 and serves residential
dwellings. It then continues away from the village to provide a route to the
crossroads within Cae Trefor.
12.6.30 However, beyond the residential dwellings the road is signed as being
“unsuitable for heavy vehicles” and therefore this is not considered to
provide a realistic option for accessing the site.
Option 3 – Junction with Bryn Goleu to the south of Croesywaun
12.6.31 This forms a simple priority junction with the A4085 and provides a route to
the crossroads at Cae Trefor. At the junction the A4085 is 8m in width with
a side road width of 8m.
12.6.32 However, Bryn Goleu serves a school and residential dwellings and in
places narrows to a single lane with restricted forward visibility, as shown
on the photographs below.
12.6.33 Furthermore, at the crossroads with Cae Trefor vehicles would be required
to undertake a right turn manoeuvre to access the quarry, as discussed
later within this chapter this could give rise to concern.
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Photograph 17 BrynGoleu junction withthe A4085
Photograph 18A4085 on theapproach to BrynGoleu
Photograph 19 BrynGoleu as it narrows
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Photograph 20 BrynGoleu restrictedforward visibility
12.6.34 Given the location of the school, residential properties within the village and
the alignment of the road, it is considered that this would not be a preferred
route to the quarry for the A4085.
Crossroads at Cae Trefor
12.6.35 As mentioned above, this would be considered to be the preferred option for
access to the quarry from the Waunfawr side of the quarry.
12.6.36 The access to the quarry passes through the crossroads junction at Cae
Trefor with the priority movement being north – south along Bryn Goleu
from Croesywaun, which then continues to eventually form a junction with
the A4086 in the north. The unnamed road, as identified in Option 1 then
forms a give way junction from the west, with the access road from the
quarry giving way from the east.
12.6.37 Due to the presence of buildings at the edge of the carriageway, visibility is
restricted from the side roads, with mirrors on adjoining buildings aiding
drivers.
12.6.38 The main road through the crossroads has a width of 5.5m, although it does
widen to 6.8m to the south of the junction, with the two side roads having
widths of 5.5m. There are no footways at the crossroads with property
directly fronting the edge of carriageway, as shown on the photographs
below.
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Photograph 21 CaeTrefor crossroadslooking north
Photograph 22 CaeTrefor crossroadslooking towards thequarry access road
Photograph 23 CaeTrefor crossroadsOption 1 route lookingnorth
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Photograph 24 CaeTrefor crossroadsOption 1 route lookingsouth
Photograph 25 CaeTrefor crossroadsaccess from thequarry looking south
Photograph 26 CaeTrefor crossroadsaccess from thequarry looking north
12.6.39 Therefore, whilst this does provide a route to the western side of the quarry
it is considered that issues of visibility, road width and on-street parking will
need to be addressed to facilitate access for construction traffic.
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Quarry Access Road
12.6.40 The access road to the quarry has a width of approximately 2.5m with a
narrow grass verge along both sides, which in places is lower than the
carriageway; this provides a direct access to the edge of the quarry site.
Photograph 27 Q1access road / GreenRoad
Photograph 28 Q1access road / GreenRoad
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Photograph 29 Q1access road / GreenRoad
12.6.41 This road will provide a direct route to the site, but due to the restricted road
width localised widening is likely to be required to allow construction
vehicles to access the site. Furthermore, as the construction vehicles will
require the full road width to manoeuvre, widening to provide passing
places will also be required.
12.7 Traffic Data
12.7.1 The potential effect of the Development has been discussed with the local
highway authority, Gwynedd, and given the requirement for two points of
access into the site from the west and east the following junctions have
been identified as being of concern:
A4244 / A4086 priority junction;
A4086 / Glyn Rhonwy priority junction;
A4086 / unnamed road priority junction within the settlement of Pont-
Rug;
A4085 / unnamed road roundabout junction within Caeathro;
A4085 / unnamed road priority junction to the north of Croesywaun, and
Priority crossroads within the settlement of Cae Trefor.
12.7.2 The above will then provide the base traffic levels at the key routes to the
site from both the west and east. In addition, 12-hour all movement traffic
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counts between 07:00 and 19:00hrs were undertaken on Thursday 26th
March 2015.
Accessibility
Public Transport
12.7.3 Once operational, the Development will employ 25-35 staff and will be
accessed from the A4086 to the west of Llanberis. It is therefore important
to ensure that future employees will be able to access the site by alternative
modes of travel to the private car.
12.7.4 The A4086 is a bus route between Llanberis and Caernarfon with the
service 88 providing a 30-minute frequency service Monday to Saturday,
with an hourly service on a Sunday.
12.7.5 The service 85 also provides an hourly link between Llanberis and Bangor
Monday to Saturday. Whilst this service retains the hourly frequency during
a Sunday, it does provide a more limited period of travel throughout the
day.
12.7.6 Bus stops are located on the A4086 adjacent to the junction with Glyn
Rhonwy, approximately 425m from the industrial estate and therefore the
site is only just outside the recommended 400m walking distance to a bus
stop outlined in “Guidance for Providing Journeys on Foot” published by the
Institution of Highways and Transportation.
12.7.7 It is therefore considered that the site has the potential to be accessible for
employees wishing to access the site by public transport.
Pedestrians and Cyclists
12.7.8 The new industrial estate accessed from Glyn Rhonwy has footways and
street lighting with footways and street lighting also being provided along
the A4086 from Llanberis.
12.7.9 The centre of the industrial estate is approximately 1km from Llanberis and
as such is within the acceptable walking distance of 1km as given by the
IHT publication “Providing for Journeys on Foot” for commuting distances.
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12.7.10 The site is therefore considered to be accessible for pedestrians wishing to
access the site from Llanberis.
Road Safety
12.7.11 The previous 5 years accident data for the local highway network was
provided by Gwynedd Council, and is set out as follows.
12.7.12 Road accidents have been analysed in order to determine whether any
existing patterns occur, which could be exacerbated by the additional trips
associated with the Development. An accident report has been obtained
from Gwynedd for the last five years of available data, as outlined within the
DfT guidance. The full accident data is attached at Appendix 12-1.
12.7.13 The area of interest includes 6 sites, including; the A4244, A4085 and
A4086, as shown below, and it should be noted that no data has been
provided for the area of road in the vicinity of Waunfawr.
Table 12.6 – Incident Causation Summary – Site 1Site 1 – A4244Causation factor 2010 2011 2012 2013 2014 TOTALRear Shunt 3 1 1 5Pulls into path ofoncoming vehicle 3 1 1 1 6
Pedestrian 2 1 2 5Loss of control 1 1TOTAL 6 3 3 3 2 17
Table 12.7 – Incident Causation Summary – Site 2Site 2 – A4086 – Glyn RhonwyCausation factor 2010 2011 2012 2013 2014 TOTALRear Shunt 0Pulls into path ofoncoming vehicle 2 2
Pedestrian 0Loss of control 1 1TOTAL 0 1 2 0 0 3
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Table 12.8 – Incident Causation Summary – Site 3Site 3 – Glyn Rhonwy – High Street (Llanberis)Causation factor 2010 2011 2012 2013 2014 TOTALRear Shunt 1 1Pulls into path ofoncoming vehicle 2 2
Pedestrian 0Loss of control 1 1TOTAL 0 2 2 0 0 4
Table 12.9 – Incident Causation Summary – Site 4Site 4 – A4244-A4086 / Arterial Road JunctionCausation factor 2010 2011 2012 2013 2014 TOTALRear Shunt 3 1 1 5Pulls into path ofoncoming vehicle 3 1 3 1 1 9
Pedestrian 0Loss of control 1 1 2TOTAL 6 2 5 2 1 16
Table 12.10 – Incident Causation Summary – Site 5Site 5 – Arterial Road Junction – CaernarfonCausation factor 2010 2011 2012 2013 2014 TOTALRear Shunt 1 1 1 3Pulls into path ofoncoming vehicle 2 1 2 5
Pedestrian 0Loss of control 1 1 3 1 6TOTAL 1 4 1 5 3 14
Table 12.11 – Incident Causation Summary – Site 6Site 6 – A4085 Waunfawr Roundabout – WaunfawrCausation factor 2010 2011 2012 2013 2014 TOTALRear Shunt 1 1 2Pulls into path ofoncoming vehicle 1 1
Pedestrian 1 1Loss of control 1Bus 0
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TOTAL 2 3 0 0 0 5
Table 12.12 – Incident Causation Summary – Site 7Site 7 – Incident Summary – All sitesCausation factor 2010 2011 2012 2013 2014 TOTALRear Shunt 7 2 3 3 1 16Pulls into path ofoncoming vehicle 6 7 6 2 4 25
Pedestrian 3 1 4 8Loss of control 2 3 3 4 12TOTAL 15 15 13 9 9 61
Summary
12.7.14 A total of 61 incidents were reported throughout the five year period
between 2010 and 2014, of which 77% were slight in severity. The accident
analysis suggests that the primary causes of accidents that have occurred
during the five years were due to lack of driver awareness and loss of
control, not as a consequence of any deficiencies in the road network itself.
It is also worth noting that that since 2011, the number of incidents within
the scoping area has reduced from 15 to 9. It is therefore considered that
the additional development traffic would not impact upon road safety on the
road network.
12.8 Potential Effects
12.8.1 The potential effects from the Development will relate to the construction
phase as once operational, the Development is not considered to result in
any material effect on the highway network.
Trip Generation
12.8.2 The Development will be split into two phases, the initial construction phase
and the operational phase and the likely traffic generation from each can be
set out as follows, and it should be noted that the traffic numbers used to
assess the percentage impact have been increased by 25% from those
given in the Construction Trip Generation tables in order to provide a level
of robustness.
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Construction Phase
12.8.3 During the construction phase, access will be required to both sides of the
quarry system, Q1 on the Waunfawr side (west) and Q6 on the Llanberis
side (east) of the site.
12.8.4 The number of vehicles that are required at each site during the life of the
construction works have been split into the following activities:
Q1 – Headpond and Associated Works
Establish Construction Compound;
On-Site Access Modifications;
Off-Site Access Modifications; and
Headpond Construction.
Q6 – Power House, Tailpond and Associated Works
Establish Construction Compound;
On-Site Access Road Modifications;
Power House Construction;
Tailpond Construction;
Penstock and Tailrace; and
Llyn Padarn pumping station / spillway infrastructure.
12.8.5 The main items of large plant are summarised below and swept path
analysis has been undertaken for access from both sides of the
Development for the following vehicle types; these are included within
Volume 4, Figures 12.1-12.5.
Low Loader with a Moxy MT41;
Low Loader with a JCB JS360;
Low Loader with a CAT D6N Dozer, and
400T Mobile Crane.
12.8.6 With reference to the swept path analysis, it can be seen that all vehicle
types will be able to access the site along both the minor access road past
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Waunfawr and from Glyn Rhonwy on the Llanberis side, albeit that
improvements within the assumed highway boundary will be required.
Q1 Headpond
12.8.7 Construction of Q1 on the upper Waunfawr side is envisaged to last for a
period of approximately 29 months. The works will be carried out during the
first six months, with the headpond construction starting in month 7 and
continuing for a further 23 months.
12.8.8 There will be no construction traffic between months 40 and the end of the
construction phase at this location.
12.8.9 The traffic generation is spilt into weekly trips, based on an average of 4
weeks per month, and daily trips based on a 5 day working week.
12.8.10 The construction traffic to access the Q1 site would travel from the A4085
via the unnamed road (known locally as Green Road) through the
crossroads at Cae Trefor using the existing access track, with all HGVs and
abnormal loads arriving and departing from the A4085 (N).
12.8.11 The construction workforce would be likely to commute from the main local
population areas of either Llanberis or Caernarfon.
Q6 Power House, Tailpond, Tunnel, Pumping Station and Associated
Works
12.8.12 The construction of the Power House, Tailpond and Associated Works at
the Glyn Rhonwy Industrial Estate and Llyn Padarn is envisaged to have a
construction period of approximately 48 months. Construction works will
mobilise in Month 1, with the main works on the Power House starting in
Month 6, continuing until Month 36.
12.8.13 The Tailpond construction will last from Month 7 to 29, with Tunnel and
Pumping Station construction lasting from Month 7 to 39.
12.8.14 There will be no construction traffic from Month 40 until Month 49 when the
site de-mobilisation will be carried out.
12.8.15 The traffic generation is spilt into weekly trips, based on an average of 4
weeks per month, and daily trips based on a 5 day working week.
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12.8.16 The construction traffic for the Q6 construction phase will use the A4086
and Glyn Rhonwy to access the quarry through the industrial estate from
Glyn Rhonwy. All HGV movements and abnormal loads would use the
A4244 to the north and would not travel through Llanberis to the south.
12.8.17 Ffordd Clegir will not be used by traffic during the construction period,
however it may be necessary to close the road temporarily for short periods
whilst drilling or blasting operations are undertaken for health and safety
reasons.
12.8.18 The construction workforce would be likely to be housed in the main local
population areas of either Llanberis or Caernarfon.
12.8.19 The total traffic to be generated by each individual element of the Q1
construction phase is shown in Tables 12-13 to 12-16.
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Table 12-13 Q1 Establish Construction Compound - Trip Generation (total over a 2 month period)Type of vehicle/plant: Number
of unitsTotal
Movements InTotal
MovementsOut
Comments
Doosan Moxy MT41 1 1 1 On site only, Lowloader deliveryJCB JS360 Backactor 0 0 0 On site only, Lowloader deliveryLong-reach Backactor excavator 0 0 0 On site only, Lowloader deliveryPneumatic breakers (‘peckers’) 0 0 0 On site only, Lowloader deliveryCaterpillar D6N dozer 0 0 0 On site only, Lowloader deliveryLarge self-propelled roller 1 1 1 On site only, Lowloader deliveryCat 374 1 1 1 On site only, Lowloader deliveryMobile crushing plant 1 1 1 On site only, Lowloader deliveryLarge Crusher 0 0 0 On site only, Lowloader deliveryLarge self-propelled Grader 1 1 1 On site only, Lowloader deliveryConstruction worker bus 6 1 1 Drop off morning, pickup evening.Site Engineers etc. 2 4 4 Cars / vans / 4WDs
Table 12-14 Q1 On-Site Access Modifications - Trip Generation (total over a 1 month period)Type of vehicle/plant: Number
of unitsTotal
Movements InTotal
MovementsOut
Comments
Doosan Moxy MT41 0 0 0 On site only, Lowloader deliveryJCB JS360 Backactor 0 0 0 On site only, Lowloader deliveryLong-reach Backactor excavator 0 0 0 On site only, Lowloader deliveryPneumatic breakers (‘peckers’) 0 0 0 On site only, Lowloader deliveryRoad surface paver 2 1 1 On site only, Lowloader deliveryCaterpillar D6N dozer 6 1 1 On site only, Lowloader delivery
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Table 12-14 Q1 On-Site Access Modifications - Trip Generation (total over a 1 month period)Type of vehicle/plant: Number
of unitsTotal
Movements InTotal
MovementsOut
Comments
Large self-propelled roller 2 1 1 On site only, Lowloader deliveryLarge Crusher 2 1 1 On site only, Lowloader deliveryLarge self-propelled Grader 2 1 1 On site only, Lowloader deliveryCat 374 2 1 1 On site only, Lowloader deliveryConstruction worker bus 32 1 1 Drop off morning, pickup evening.Site Engineers etc. 8 4 4 Cars / vans / 4WDs
Table 12-15 Q1 Off-Site Access Modifications - Trip Generation (total over a 1 month period)Type of vehicle/plant: Number
of unitsTotal
Movements InTotal
MovementsOut
Comments
Doosan Moxy MT41 1 1 1 On site only, Lowloader deliveryRoad haulage (tipper trucks) 4 4 4 Self-propelledLong-reach Backactor excavator 0 0 0 On site only, Lowloader deliveryRoad surface paver 1 1 1 On site only, Lowloader deliveryPneumatic breakers (‘peckers’) 0 0 0 On site only, Lowloader deliveryCaterpillar D6N dozer 0 0 0 On site only, Lowloader deliveryLarge self-propelled roller 1 1 1 On site only, Lowloader deliveryLarge Crusher 0 0 0 On site only, Lowloader deliveryLarge self-propelled Grader 1 1 1 On site only, Lowloader deliveryCat 374 1 1 1 On site only, Lowloader deliveryExcavated material 4 4 4 Self-propelledAggregate Deliveries 4 4 4 Self-propelledConstruction worker bus 9 1 1 Drop off morning, pickup evening.
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Table 12-14 Q1 On-Site Access Modifications - Trip Generation (total over a 1 month period)Type of vehicle/plant: Number
of unitsTotal
Movements InTotal
MovementsOut
Comments
Site Engineers etc. 2 8 8 Cars / vans / 4WDs
Table 12-16 Q1 Headpond - Construction Trip Generation (total over a 23 month period)Type of vehicle/plant: Number
of unitsTotal
Movements InTotal
MovementsOut
Comments
Doosan Moxy MT41 13 13 13 On site only, Lowloader deliveryJCB JS360 Backactor 6 6 6 On site only, Lowloader deliveryLong-reach Backactor excavator 4 4 4 On site only, Lowloader deliveryPneumatic breakers (‘peckers’) 2 2 2 On site only, Lowloader deliveryCaterpillar D6N dozer 17 17 17 On site only, Lowloader deliveryLarge self-propelled roller 3 3 3 On site only, Lowloader deliveryLarge Crusher 6 6 6 On site only, Lowloader deliveryLarge self-propelled Grader 5 5 5 On site only, Lowloader deliverySprayed concrete batching plant 2 2 2 On site only, Lowloader deliveryWater Pump 1 1 1 On site only, Lowloader deliveryFiltration, ‘Siltbuster’ type 1 1 1 On site only, Lowloader deliverySelf-propelled or tractor-towedwater bowsers (for dustsuppression, water supply)
2 2 2 On site only, Lowloader delivery
Generators 2 2 2 On site only, Lowloader deliveryCompressors for compressed airsupply 2 2 2 On site only, Lowloader delivery
Telehandlers 2 2 2 On site only, Lowloader delivery
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Table 12-16 Q1 Headpond - Construction Trip Generation (total over a 23 month period)Type of vehicle/plant: Number
of unitsTotal
Movements InTotal
MovementsOut
Comments
Concrete pumps 3 3 3 On site only, Lowloader deliveryAccess platforms (‘cherry pickers’) 4 4 4 Material deliveries to siteConveyor systems 4 12 12 Self-propelledLarge Loading shovel 2 2 2 Deliveries to site, 40T articTracked drilling plant 2 2 2 Deliveries to siteCat 374 9 9 9 On site only, Lowloader deliveryDrill rigs (blasting) 5 6 6 Deliveries to siteDrill rigs (grouting) 8 8 8 On site only, Lowloader deliveryDrill rigs (rock anchors) 3 3 3 Deliveries to site, vanMiscellaneous plant deliveries 100 100 100 Deliveries to site, 40T articTower crane (with grab forexcavation) 2 4 4 Deliveries to site, van
Explosives delivery (ANFOtanker) 1 30 30 Deliveries to site, 40T artic
Mobile crane 3 3 3 Deliveries to site, 40T articHDPE membrane delivery 1 5 5 Deliveries to site, 40T articConcrete Delivery Truck 1 100 100 On site only, Lowloader deliveryCompressors 2 2 2 On site only, Lowloader deliveryGrout Delivery Truck 1 30 30 Wide load (4m min), possibly 4.5mGrout batching plant 4 4 4 Deliveries to site, 40T articPlant maintenance van 1 150 150 Deliveries to site, 40T articSite cabins delivery 1 5 5 Drop off morning, pickup evening.Site cabins servicing van 1 100 100 Cars / vans / 4WDsReinforcement steel deliveries 1 10 10 On site only, Lowloader deliveryScour/Spill pipe deliveries 1 15 15 On site only, Lowloader delivery
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Table 12-16 Q1 Headpond - Construction Trip Generation (total over a 23 month period)Type of vehicle/plant: Number
of unitsTotal
Movements InTotal
MovementsOut
Comments
Scour/Spill pipe valves etc. 1 1 1 On site only, Lowloader deliveryPermanent Fence 4165 172 172 On site only, Lowloader deliveryTemp. Fencing 1190 14 14 On site only, Lowloader deliveryOutlet pipe section 1 1 1 On site only, Lowloader deliveryOutlet pipe valves etc. 2 2 2 On site only, Lowloader deliveryRock anchors deliveries 1 15 15 On site only, Lowloader deliveryConstruction worker bus 1 1080 1080 On site only, Lowloader deliverySite Engineers etc. 3 8100 8100 On site only, Lowloader delivery
12.8.20 The total traffic to be generated by each individual element of the Q6 construction phase is shown in Table 12-17 to 12-22.
Table 12-17 Q6 Establish Construction Compound - Trip Generation (total over a 2 month period)Type of vehicle/plant: Number
of unitsTotal
Movements InTotal
MovementsOut
Comments
Doosan Moxy MT41 1 1 1 On site only, Lowloader deliveryJCB JS360 Backactor 0 0 0 On site only, Lowloader deliveryLong-reach Backactor excavator 0 0 0 On site only, Lowloader deliveryPneumatic breakers (‘peckers’) 0 0 0 On site only, Lowloader deliveryCaterpillar D6N dozer 0 0 0 On site only, Lowloader deliveryLarge self-propelled roller 1 1 1 On site only, Lowloader deliveryCat 374 1 1 1 On site only, Lowloader deliveryMobile crushing plant 1 1 1 On site only, Lowloader deliveryLarge Crusher 0 0 0 On site only, Lowloader delivery
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Table 12-17 Q6 Establish Construction Compound - Trip Generation (total over a 2 month period)Type of vehicle/plant: Number
of unitsTotal
Movements InTotal
MovementsOut
Comments
Large self-propelled Grader 1 1 1 On site only, Lowloader deliveryConstruction worker bus 10 1 1 Drop off morning, pickup evening.Site Engineers etc. 2 4 4 Cars / vans / 4WDs
Table 12-18 Q6 On-Site Access Modifications - Trip Generation (total over a 1 month period)Type of vehicle/plant: Number
of unitsTotal
Movements InTotal
MovementsOut
Comments
Doosan Moxy MT41 0 0 0 On site only, Lowloader deliveryJCB JS360 Backactor 0 0 0 On site only, Lowloader deliveryLong-reach Backactor excavator 0 0 0 On site only, Lowloader deliveryPneumatic breakers (‘peckers’) 0 0 0 On site only, Lowloader deliveryRoad surface paver 2 1 1 On site only, Lowloader deliveryCaterpillar D6N dozer 6 1 1 On site only, Lowloader deliveryLarge self-propelled roller 2 1 1 On site only, Lowloader deliveryLarge Crusher 2 1 1 On site only, Lowloader deliveryLarge self-propelled Grader 2 1 1 On site only, Lowloader deliveryCat 374 2 1 1 On site only, Lowloader deliveryConstruction worker bus 32 1 1 Drop off morning, pickup evening.Site Engineers etc. 8 4 4 Cars / vans / 4WDs
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Table 12-19 Q6 Power House - Construction Trip Generation (total over a 37 month period)Type of vehicle/plant: Number of
unitsNumber of
movements(in and out)for each unit
Comments
Doosan Moxy MT41 2 2 On site only, Lowloader deliveryJCB JS360 Backactor 1 1 On site only, Lowloader deliveryLong-reach Backactor excavator 1 1 On site only, Lowloader deliveryCaterpillar D6N dozer 0 0 On site only, Lowloader deliveryCaterpillar 374 2 0 On site only, Lowloader deliveryLarge self-propelled roller 0 0 On site only, Lowloader deliveryLarge Crusher 1 1 On site only, Lowloader deliveryLarge self-propelled Grader 0 0 On site only, Lowloader deliveryLarge Loading shovel 2 1 On site only, Lowloader deliveryDrill rigs (blasting) 2 2 On site only, Lowloader deliveryDrill rigs (grouting) 1 1 On site only, Lowloader deliveryPumps 2 2 On site only, Lowloader deliveryFiltration, ‘Siltbuster’ type 2 2 On site only, Lowloader deliveryRock bolt drill 1 1 On site only, Lowloader deliveryExplosives delivery (ANFO tanker) 1 20 Material deliveries to siteAccess Platform 6 6 On site only, Lowloader deliveryScissor Lifts 6 6 On site only, Lowloader deliveryMobile crane 1 1 Self-propelledConcrete Delivery Truck 1 50 Deliveries to siteGrout Delivery Truck 1 15 Deliveries to siteGrout batching plant 1 1 Deliveries to site, 40T articConcrete batching plant 3 3 On site only, Lowloader deliveryConcrete Pumps 3 3 On site only, Lowloader deliveryPlant maintenance van 1 300 Deliveries to site, van
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Table 12-19 Q6 Power House - Construction Trip Generation (total over a 37 month period)Type of vehicle/plant: Number of
unitsNumber of
movements(in and out)for each unit
Comments
Site cabins delivery 1 5 Deliveries to site, 40T articReinforcement steel deliveries 1 10 Deliveries to site, 40T articPipe deliveries 1 15 Deliveries to site, 40T artic
Construction workers 1 1440Drop off morning, pickup evening. Alternative is provideparking at Q6 (with subsequent inc. in vehiclemovements). 360 days x 3 years.
Tower crane (with grab forexcavation) 6 12 Deliveries to site, 40T artic
Turbine delivery 4 32 Wide load (4m min), possibly 4.5mLarge Pipes deliveries 6 36 Wide load (4m min), possibly 4.5mOther M&E plant delivery 1 10 Deliveries to site, 40T articBuilding steel frame 1 5 Deliveries to site, 40T articBuilding cladding 1 10 Deliveries to site, 40T articBuilding ancillaries 1 20 Deliveries to site, 40T articMiscellaneous plant deliveries 100 100 Allowance, lowloader or 40T artic delivery
Site Engineers etc. 3 16200 Cars / vans / 4WDsDaily vehicle trips
Table 12-20 Q6 Tailpond - Construction Trip Generation (total over a 23 month period)Type of vehicle/plant: Number of
unitsNumber ofmovements(in and out)
for each unit
Comments
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Table 12-20 Q6 Tailpond - Construction Trip Generation (total over a 23 month period)Type of vehicle/plant: Number of
unitsNumber ofmovements(in and out)
for each unit
Comments
Doosan Moxy MT41 16 16 On site only, Lowloader deliveryJCB JS360 Backactor 2 2 On site only, Lowloader deliveryLong-reach Backactor excavator 3 3 On site only, Lowloader deliveryCat 374 10 10 On site only, Lowloader deliveryPneumatic breakers (‘peckers’) 2 2 On site only, Lowloader deliveryCaterpillar D6N dozer 12 12 On site only, Lowloader deliveryLarge self-propelled roller 4 4 On site only, Lowloader deliveryLarge Crusher 4 4 On site only, Lowloader deliveryLarge self-propelled Grader 6 6 On site only, Lowloader deliveryConcrete Batching Pant 2 2 On site only, Lowloader deliveryConcrete Pumps 2 2 On site only, Lowloader deliveryConveyor systems 4 12 On site only, Lowloader deliveryLarge Loading shovel 2 2 On site only, Lowloader deliveryDrill rigs (blasting) 10 10 On site only, Lowloader deliveryCompressor 4 4 On site only, Lowloader deliveryAccess platforms (‘cherry pickers’) 6 6 On site only, Lowloader deliveryMobile crushing plantMobile screening plant 2 2 On site only, Lowloader delivery
Water Pump 1 1 On site only, Lowloader deliveryFiltration, ‘Siltbuster’ type 1 1 On site only, Lowloader deliverySelf-propelled or tractor-towed waterbowsers (for dust suppression, watersupply)
2 2 On site only, Lowloader delivery
Generators 2 2 On site only, Lowloader delivery
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Table 12-20 Q6 Tailpond - Construction Trip Generation (total over a 23 month period)Type of vehicle/plant: Number of
unitsNumber ofmovements(in and out)
for each unit
Comments
Compressors for compressed airsupply 2 2 On site only, Lowloader delivery
Telehandlers 2 2 On site only, Lowloader deliveryConcrete pumps 3 3 On site only, Lowloader deliveryDrill rigs (grouting) 6 6 On site only, Lowloader deliveryExplosives delivery (ANFO tanker) 1 10 Material deliveries to siteTower Crane 2 2 On site only, Lowloader deliveryMobile crane 6 6 Self-propelledConcrete Delivery Truck 1 30 Deliveries to siteGrout Delivery Truck 1 30 Deliveries to siteGrout batching plant 4 4 Deliveries to site, 40T articPlant maintenance van 1 100 Deliveries to site, vanSite cabins delivery 1 5 Deliveries to site, 40T articReinforcement steel deliveries 1 10 Deliveries to site, 40T articPermanent Fence 3243 63 On site only, Lowloader deliveryTemp. Fencing 930 11 On site only, Lowloader deliveryPipe deliveries 1 15 Deliveries to site, 40T articRock anchors deliveries 1 30 Deliveries to site, 40T artic
Construction workers 1 450Drop off morning, pickup evening. Alternative is provideparking at Q6 (with subsequent inc. in vehiclemovements)
Site Engineers etc. 3 6750 Cars / vans / 4WDs
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Table 12-21 Penstock Tunnel Construction - Trip Generation (total over a 34 month period)Type of vehicle/plant: Number of
unitsNumber ofmovements(in and out)
for each unit
Comments
Doosan Moxy MT41 4 4 On site only, Lowloader deliveryLarge Loading shovel 0 0 On site only, Lowloader deliveryConcrete Delivery Truck 1 1000 On site only, Lowloader deliveryPlant maintenance van 1 540 Large Rigid HGVSite cabins delivery 1 5 Deliveries to site, 40T articReinforcement steel deliveries forlining 1 500 Deliveries to site, 40T artic
Precast segment deliveries for lining 1 1000 Deliveries to site, 40T articTunnelling Machinery delivery (in) 5mdiameter 1 7 On site only, Lowloader delivery
Tunnelling Machinery removal (out)5m diameter 1 1 On site only, Lowloader delivery
Mobile Crushing Plant 1 1 On site only, Lowloader deliveryGrout batching plant 1 1 On site only, Lowloader deliveryConcrete batching plant 1 1 On site only, Lowloader deliveryConcrete Former 4 4 On site only, Lowloader deliveryScissor Lifts 1 1 On site only, Lowloader deliveryRock bolt drill 1 1 On site only, Lowloader deliveryCat 374 1 1 On site only, Lowloader deliveryMobile Crane 1 1 Self-PropelledBelt conveyor system 160 160 On site only, Lowloader deliveryConstruction workers 1 1080 Cars / vans / 4WDs
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Table 12-21 Penstock Tunnel Construction - Trip Generation (total over a 34 month period)Type of vehicle/plant: Number of
unitsNumber ofmovements(in and out)
for each unit
Comments
Temporary ventilation plant 1 10 Large Rigid HGVSite Engineers etc. 3 8100 Drop off morning, pickup evening.
Table 12-22 Llyn Padarn Pumping Station / Spillway Infrastructure Construction - Trip Generation (total over a 33 monthperiod)Type of vehicle/plant: Number of
unitsNumber ofmovements(in and out)
for each unit
Comments
JCB JS360 Backactor 2 2 On site only, Lowloader deliveryMobile crane 1 1 Self-propelledConcrete Delivery Truck 2 10 Deliveries to sitePlant maintenance van 1 24 Deliveries to site, vanReinforcement steel deliveries 2 2 Deliveries to site, 40T articPipe deliveries 25 25 Deliveries to site, 40T artic, 25Construction workers 1 360 Drop off morning, pickup evening.Scour / spillway Pipes deliveries (twinpipes, 10m sections, 300m length) 600 600 Deliveries to site, 40T artic
Other M&E plant delivery 5 5 Deliveries to site, 40T articSite Engineers etc. 2 720 Cars / vans / 4WDsSilt Busters 4 1 On site only, Lowloader deliveryPumps 3 1 On site only, Lowloader delivery
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Operational Phase
12.8.21 Once operational the Development will employ up to 25-35 staff, some of
which will likely work on a 3-shift pattern, with others working normal office
hours.
12.8.22 As the staff will be located at the Power House then regular vehicular
access will only be required from the A4086 to the eastern side of the
quarry (Q6), with only periodic access required for maintenance from the
western side.
12.8.23 The evaluation of the significance of the potential effects is presented in
Table 12-23 and 12-24 for the Construction Period and Table 12-25 for the
Operational Period.
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Table 12-23 Evaluation of Significance (Construction Phase) Pre-Mitigation
Nature of Effect Receptor Effect Significance of Effect ConfidenceLevel
Q1 Waunfawr Construction
Additional HGVs throughthe crossroads atWaunfawr
Local Moderate AdverseMinor AdverseConstruction traffic on theminor access road
High
Additional cars / vansthrough the crossroads atWaunfawr
Local Moderate Adverse Minor Adverse due to trafficon the minor access road High
Construction ofsite/Development Borough / District Moderate Adverse
Minor AdverseConstruction Traffic onroad network.
High
Severance at Waunfawr Local Moderate AdverseMinor Adverse effect due toincrease in vehiclemovements
High
Road Safety Local Negligible Negligible - no existingissues identified. High
Pedestrians and Cyclist Local Negligible / MinorAdverse
Negligible / Minor Adverseeffect of pedestrians andcyclists
High
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Table 12-23 Evaluation of Significance (Construction Phase) Pre-Mitigation
Nature of Effect Receptor Effect Significance of Effect ConfidenceLevel
Public Transport Local Negligible / MinorAdverse
Negligible / Minor Adverseeffect on public transport High
Driver Delay Local Minor Adverse Minor Adverse effect due toadditional HGV movements High
Increase in traffic flows Local Negligible / MinorAdverse
Negligible / Minor Adverseeffect on traffic flows on thenetwork
High
Table 12-24 Evaluation of Significance (Construction Phase) Pre-Mitigation
Nature of Effect Receptor Environmental Effect Significance of Effect Confidence Level
Q6 Llanberis Construction
Additional HGVs on GlynRhonwy Local Moderate Adverse
Minor AdverseConstruction traffic onGlyn Rhonwy
High
Additional cars / vans onGlyn Rhonwy Local Moderate Adverse Minor Adverse due to
traffic on Glyn Rhonwy High
Construction ofsite/Development Borough / District Moderate Adverse
Minor AdverseConstruction Traffic onroad network.
High
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Table 12-24 Evaluation of Significance (Construction Phase) Pre-Mitigation
Nature of Effect Receptor Environmental Effect Significance of Effect Confidence Level
Road Safety Local Negligible Negligible - no existingissues identified. High
Pedestrians and Cyclist Local Negligible / MinorAdverse
Negligible / MinorAdverse effect ofpedestrians and cyclists
High
Public Transport Local Negligible / MinorAdverse
Negligible / MinorAdverse effect on publictransport
High
Driver Delay Local Minor AdverseMinor Adverse effect dueto additional HGVmovements
High
Increase in traffic flows Local Negligible / MinorAdverse
Negligible / MinorAdverse effect on trafficflows on the network
High
Table 12-25 Evaluation of Significance (Operational Phase) Pre-Mitigation
Nature of Effect Receptor Environmental Effect Significance of Effect Confidence Level
Site Operation
AdditionalDevelopment trafficon Glyn Rhonwy
Borough / District andLocal Moderate Adverse
Minor AdverseAdditional traffic on GlynRhonwy and the A4086
High
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Table 12-25 Evaluation of Significance (Operational Phase) Pre-Mitigation
Nature of Effect Receptor Environmental Effect Significance of Effect Confidence Level
AdditionalDevelopment trafficthrough Waunfawr
Borough / District andLocal / Neighbourhood Moderate Adverse
Minor AdverseAdditional traffic the minoraccess road and the A4086
High
Severance Local Negligible to MinorAdverse
Negligible to MinorAdverse effect fromincreased traffic on theA4086 and Glyn Rhonwy
High
Road Safety Local Negligible Negligible - no existingissues identified. High
Pedestrians andCyclists Local Minor Positive Minor Adverse due to links
into Llanberis High
Public Transport Local Minor Adverse Minor Adverse effect dueto increased demand. High
Driver Delay Local Minor Adverse Minor Adverse due toincreased traffic. High
Increase in TrafficFlow Local Minor Adverse
Minor Adverse effect fromincrease in traffic on linksand junctions.
High
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Construction Traffic Impacts
12.8.24 A number of months (1, 7, 18, 29, 33 and 38) have been chosen to
represent key periods during the construction phase, as described below:
Month 1 – First month of construction phase;
Month 7 – First peak of construction traffic;
Month 18 –‘Normal’ levels of construction traffic;
Month 29 – Second peak of construction traffic; and
Months 33 & 38 – Low levels of construction traffic.
12.8.25 The total average number of daily vehicles generated by the two portions of
the Development is shown graphically in a generated traffic profile graph in
Figure 12-6. This shows the average number of daily vehicles expected per
month during the construction phase and highlights the reasoning behind
using the months stated above.
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Figure 12-7 Average Daily Vehicle Movements by Month during the Construction Phase
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12.8.26 In Figure 12-6, the ‘Worker Daily’ movements represent the total vehicles
attributed to staff arriving and departing the sites. The ‘Car Daily’
movements represent the transit of vehicles between the two site
compounds during the day. The ‘HGV Daily’ movements represent the total
HGV movements in and out of the sites.
12.8.27 The average daily construction traffic for the key months generated by both
portions of the Development have been combined and subsequently added
to the predicted 2017 Base two-way traffic flows. Consequently, a
percentage change has been calculated to provide an indication of the level
of impact generated by the traffic upon key junctions and road links. This
shown in Table 12-26 to Table 12-31. Further information, including a
breakdown of impacts generated by the Q1 and Q6 construction phases, is
provided in Appendix 12-2.
Table 12-26 Q1 and Q6 Construction Traffic Effects - Month 1
Junction LinkPredicted2017 TwoWay Daily
Flow
DevelopmentPCUs % Increase
WaunfawrCrossroads
Green Road (eastof crossroads) 305 48 16%
Green Road (westof crossroads) 510 48 9%
A4085Waunfawr
Green Road 701 48 7%A4085 (W) 3519 48 1%A4085 (E) 3139 0 0%
A4086 / GlynRhonwy
Glyn Rhonwy 830 81 10%A4086 (W) 6329 80 1%A4086 (E) 5847 3 0%
A4086 / A422A4244 6956 41 1%A4086 (W) 6683 50 1%A4086 (E) 6721 80 1%
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Table 12-27 Q1 and Q6 Effects on Links - Month 7
Junction LinkPredicted2017 TwoWay Daily
Flow
DevelopmentPCUs
PercentageIncrease
WaunfawrCrossroads
Green Road (east ofcrossroads) 305 299 98%
Green Road (westof crossroads) 510 299 59%
A4085Waunfawr
Green Road 701 299 43%A4085 (W) 3519 299 8%A4085 (E) 3139 0 0%
A4086 / GlynRhonwy
Glyn Rhonwy 830 347 42%A4086 (W) 6329 311 5%A4086 (E) 5847 42 1%
A4086 / A422A4244 6956 213 3%A4086 (W) 6683 334 5%A4086 (E) 6721 311 5%
Table 12-28 Q1 and Q6 Effects on Links - Month 18
Junction LinkPredicted2017 TwoWay Daily
Flow
DevelopmentPCUs
PercentageIncrease
WaunfawrCrossroads
Green Road (east ofcrossroads) 305 195 64%
Green Road (westof crossroads) 510 195 38%
A4085Waunfawr
Green Road 701 195 28%A4085 (W) 3519 195 6%A4085 (E) 3139 0 0%
A4086 / GlynRhonwy
Glyn Rhonwy 830 247 30%A4086 (W) 6329 230 4%A4086 (E) 5847 24 0%
A4086 / A422A4244 6956 103 1%A4086 (W) 6683 212 3%A4086 (E) 6721 230 3%
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Table 12-29 Q1 and Q6 Effects on Links - Month 29
Junction LinkPredicted2017 TwoWay Daily
Flow
DevelopmentPCUs
PercentageIncrease
WaunfawrCrossroads
Green Road (east ofcrossroads) 305 341 112%
Green Road (westof crossroads) 510 341 67%
A4085Waunfawr
Green Road 701 341 49%A4085 (W) 3519 341 10%A4085 (E) 3139 0 0%
A4086 / GlynRhonwy
Glyn Rhonwy 830 327 39%A4086 (W) 6329 306 5%A4086 (E) 5847 28 0%
A4086 / A422A4244 6956 270 4%A4086 (W) 6683 362 5%A4086 (E) 6721 306 5%
Table 12-30 Q1 and Q6 Effects on Links - Month 33
Junction LinkPredicted2017 TwoWay Daily
Flow
DevelopmentPCUs
PercentageIncrease
WaunfawrCrossroads
Green Road (east ofcrossroads) 305 53 17%
Green Road (westof crossroads) 510 53 10%
A4085Waunfawr
Green Road 701 53 8%A4085 (W) 3519 53 2%A4085 (E) 3139 0 0%
A4086 / GlynRhonwy
Glyn Rhonwy 830 118 14%A4086 (W) 6329 113 2%A4086 (E) 5847 5 0%
A4086 / A422A4244 6956 55 1%A4086 (W) 6683 58 1%A4086 (E) 6721 113 2%
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Table 12-31 Q1 and Q6 Effects on Links - Month 38
Junction LinkPredicted2017 TwoWay Daily
Flow
DevelopmentPCUs
PercentageIncrease
WaunfawrCrossroads
Green Road (east ofcrossroads) 305 14 5%
Green Road (westof crossroads) 510 14 3%
A4085Waunfawr
Green Road 701 14 2%A4085 (W) 3519 14 0%A4085 (E) 3139 0 0%
A4086 / GlynRhonwy
Glyn Rhonwy 830 75 9%A4086 (W) 6329 71 1%A4086 (E) 5847 3 0%
A4086 / A422A4244 6956 53 1%A4086 (W) 6683 18 0%A4086 (E) 6721 71 1%
Waunfawr Crossroads
12.8.28 During the first peak of construction (Month 7), there would be a 98%
increase in traffic on Green Road to the east of the junction and a 59%
increase in traffic on Green Road to the west of the junction. During the
second peak of construction (Month 29), there would be a 112% increase in
traffic on Green Road to the east of the junction and a 67% increase in
traffic on Green Road to the west of the junction.
12.8.29 The large percentage increase in traffic at the junction is in part attributed to
the low base traffic levels on the minor roads. It should be noted that the
peak levels of construction traffic would only be expected over the two
months specified and the remaining months would represent lower traffic
levels.
12.8.30 During ‘normal’ construction traffic conditions (represented by Month 18),
there would be a 64% increase in traffic on Green Road to the east of the
junction and a 38% increase in traffic on Green Road to the west of the
junction. As with the peak construction months, the level of percentage
increases are largely attributed to the low base traffic levels on the minor
roads.
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12.8.31 In order to mitigate the impacts of the construction traffic, improvements at
the crossroads have been proposed. Located at the crossroads there is to
be either a four-way traffic light system or banksmen with stop / go boards
throughout the whole construction process. Prior to any of the construction
works starting a full schedule and plans showing the proposed traffic
management procedures will be provided to Gwynedd Council for approval
as part of the finalised CTMP.
A4086 / Glyn Rhonwy
12.8.32 During the first peak of construction (Month 7), there would be a 42%
increase in traffic on the Glyn Rhonwy link of the junction and a 39%
increase during the second peak of construction (Month 29).
12.8.33 During ‘normal’ construction traffic conditions, there would not be an
increase in traffic above 30%.
12.8.34 The percentage increase in traffic at the junction during the peak
construction periods is in part attributed to the low base traffic levels on the
Glyn Rhonwy link. It should be noted that the peak levels of construction
traffic would only be expected over the two months specified and the
remaining months would represent lower traffic levels. Additionally, the Glyn
Rhonwy link is an industrial road with no residential properties, therefore the
increase in traffic is considered acceptable.
A4085 Waunfawr
12.8.35 During the first peak of construction (Month 7), there would be a 43%
increase in traffic on Green Road. During the second peak of construction
(Month 29), there would be a 49% increase in traffic.
12.8.36 During ‘normal’ construction traffic conditions, there would not be an
increase in traffic above 30%.
12.8.37 The percentage increase in traffic at the junction during the peak
construction periods is in part attributed to the low base traffic levels on the
Green Road link. It should be noted that the peak levels of construction
traffic would only be expected over the two months specified and the
remaining months would represent lower traffic levels.
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A4086 / A422
12.8.38 During all phases of the construction period, there would not be an increase
in traffic of more than 5%.
12.9 Mitigation, Compensation and Enhancement Measures
12.9.1 The following summarises the proposed measures which are designed to
mitigate the potential effects on each of the environmental receptors.
Construction Effects
12.9.2 The number of HGVs associated with construction traffic is likely to have an
adverse, but temporary, effect on the local highway network, and therefore
the programming of such movements will be subject to restricted periods of
the day and working week. It is envisaged that such periods will be
restricted to 07:00-19:00 Monday to Friday and 07:00-13:00 Saturday with
no working on Sundays or Public Bank Holidays.
12.9.3 The Contractor will provide a detailed CTMP, incorporated in to an overall
CoCP, identifying how traffic will be managed throughout the duration of the
construction period. The CTMP will also outline how pedestrian and cyclist
traffic will be safely and effectively managed in the event of closures and /
or diversions to footpaths, footways and cycle routes due to construction
works; appropriately signed alternative routes will be provided. Any other
specific requirements will also be considered.
12.9.4 An appointed employee will liaise with all relevant bodies to ensure that
deliveries associated with construction occur outside of the peak road
network periods, so far as practically possible, to minimise delay on other
road users.
12.9.5 A Health and Safety Plan (HASP) will be required for the construction of the
Development; this will include details of good practice methods of reducing
dust emissions and wheel washing facilities. The HASP is a CDM
requirement and separate to any specific Contractor agreements to
minimise the effect of construction traffic.
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12.9.6 So far as practicable, earthwork material from the existing site will be
retained for re-use as soft landscape areas and acoustic bunding, therefore
minimising the need to import material onto site.
12.9.7 Minor highway improvements will be carried out on Green Road from
Waunfawr to Q1. These are not proposed to form part of this DCO
application but will instead be dealt with using a Section 278 Agreement
with the Local Highway Authority and will be subject to its own planning
application. The road improvements are summarised below:
Replace existing cattle grid on the Q1 access road with a heavy duty
grid. Once the works are complete the grid will either remain in place, if
still structurally sound, or be replaced if not.
Widen the existing Q1 access road carriageway to a minimum width of
4m and remove, where possible, tight bends to enable the construction
traffic to use the route.
Along the length of the Q1 access road it is proposed to incorporate
seven passing places, positioned roughly 170m apart, to enable vehicles
to travel in both directions on the single lane carriageway.
12.9.8 It is considered that with the implementation of the above measures, the
effect on pedestrians, cyclists and other road users during the construction
period will be reduced.
Operational Effects
12.9.9 Traffic flows during the operational phase of the Development will be
notably less than those experienced during the construction phase. As can
be seen from the previous tables, the construction phase traffic flows result
in a less than 30% effect when compared to base flows. Therefore, there is
no requirement to introduce off-site highway mitigation measures as part of
the proposals.
12.9.10 The Development will actively promote sustainable travel to the site through
the implementation of a Travel Plan (TP), which will contribute to the overall
accessibility of the site. It will further the aims of and objectives of Central
and Local Government Sustainable Transport Policies by promoting the use
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of alternative modes of transport and hence reducing the need for travel by
private car.
12.9.11 The TP will seek to achieve a modal shift from private car use. It is
considered that with the implementation of the above measures, the effect
on pedestrians, cyclists and other road users during the construction period
will be reduced.
Severance
12.9.12 Footways are proposed within the internal site, these footways will be
designed to provide clear pedestrian links which will link with the existing
provisions on the local network, where practical.
Road Safety
12.9.13 The review of the existing road traffic accident records did not raise any
road safety concerns or the requirement for any road safety improvement
measures.
Pedestrians and Cyclists
12.9.14 The internal site layout is designed as far as possible to accommodate the
movement of pedestrian and cyclists and on-site routes will integrate with
existing off-site routes where possible.
Public Transport
12.9.15 There are existing bus services serving the stops on the A4086 in the
vicinity of the site providing 30 minute frequency between Llanberis and
Caernarfon on Monday to Saturday; an hourly service is available on
Sundays. The service 85 also provides an hourly link between Llanberis
and Bangor on Monday to Saturday.
12.9.16 It is therefore considered that the site has the potential to be accessible for
those wishing to access the site by public transport.
12.9.17 In summary, it is considered that with the implementation of the previous
measures, the effect of traffic during the construction and operational
phases will be reduced.
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12.10 Residual Effects
12.10.1 Generally, the increase in traffic flows attributed to the construction phase
will have a minor adverse effect on the annual average daily traffic flow on
the majority of highway links. However, during certain periods of the
construction period some of the identified highway links are expected to
have an increase of greater than 30% compared with the base traffic
conditions. With the effect of mitigation on the remaining affected links, the
residual significance of effects is expected to be minor adverse, as detailed
in Table 12-32.
12.11 Evaluation of Significance
12.11.1 Table 12-32 presents a summary of the residual impacts for the
Development, accounting for the effects of mitigation measures on the
worst-case impacts as determined within this assessment.
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Table 12-32 Summary of Assessment
Description of Receptor Description of Potential Effect Description of Residual Effect
Receptor Value /Sensitivity Effect Nature of
Effect DurationMagnitude(PercentageTraffic Increase)
PotentialSignificance Summary of Mitigation Residual Effect Residual
SignificanceChangefrom 2012Chapter
Local /Neighbourhood Moderate
WaunfawrCrossroads(Green Road East)
Increase in dailyLight Vehicle andHGV movements
2 periods of 1month duringconstruction
Month 7 = 98%Month 29 = 112%
ModerateAdverse
Implementation of aConstruction Site Safety Plan(CSSM) and a Code ofConstruction Practice(CoCP)
Aim to reduce andmanage the impactfrom the additionalvehicle movements asfar as is possible.
Minor Adverse No change
WaunfawrCrossroads(Green Road West)
Increase in dailyLight Vehicle andHGV movements
2 periods of 1month duringconstruction
Month 7 = 59%Month 29 = 67%
ModerateAdverse
Implementation of aConstruction Site SafetyPlan (CSSM)and a Code ofConstruction Practice(CoCP)
Aim to reduce andmanage the impactfrom the additionalvehicle movements asfar as is possible.
Minor Adverse No change
WaunfawrCrossroads(Green Road East)
Increase in dailyLight Vehicle andHGV movements
11 monthsduring
construction64% Moderate
Adverse
Implementation of aConstruction Site SafetyPlan (CSSM) and a Code ofConstruction Practice(CoCP)
Aim to reduce andmanage the impactfrom the additionalvehicle movements asfar as is possible.
Minor Adverse No change
WaunfawrCrossroads(Green Road West)
Increase in dailyLight Vehicle andHGV movements
11 monthsduring
construction38% Moderate
Adverse
Implementation of aConstruction Site SafetyPlan (CSSM) and a Code ofConstruction Practice(CoCP)
Aim to reduce andmanage the impactfrom the additionalvehicle movements asfar as is possible.
Minor Adverse No change
A4086 / Glyn Rhonwy(Glyn Rhonwy)
Increase in dailyLight Vehicle andHGV movements
2 periods of 1month duringconstruction
Month 7 = 42%Month 29 = 39%
ModerateAdverse
Implementation of aConstruction Site SafetyPlan (CSSM) and a Code ofConstruction Practice(CoCP)
Aim to reduce andmanage the impactfrom the additionalvehicle movements asfar as is possible.
Minor Adverse No change
A4086 / Glyn Rhonwy(Glyn Rhonwy)
Increase in dailyLight Vehicle andHGV movements
11 monthsduring
construction30% Moderate
Adverse
Implementation of aConstruction Site SafetyPlan (CSSM) and a Code ofConstruction Practice(CoCP)
Aim to reduce andmanage the impactfrom the additionalvehicle movements asfar as is possible.
Minor Adverse No change
A4085 Waunfawr(Green Road)
Increase in dailyLight Vehicle andHGV movements
2 periods of 1month duringconstruction
Month 7 = 43%Month 29 = 49%
ModerateAdverse
Implementation of aConstruction Site SafetyPlan (CSSM) and a Code ofConstruction Practice(CoCP)
Aim to reduce andmanage the impactfrom the additionalvehicle movements asfar as is possible.
Minor Adverse No change
A4085 Waunfawr(Green Road)
Increase in dailyLight Vehicle andHGV movements
11 monthsduring
construction28% Moderate
Adverse
Implementation of aConstruction Site SafetyPlan (CSSM) and a Code ofConstruction Practice(CoCP)
Aim to reduce andmanage the impactfrom the additionalvehicle movements asfar as is possible.
Minor Adverse No change
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Table 12-32 Summary of Assessment
Description of Receptor Description of Potential Effect Description of Residual Effect
Receptor Value /Sensitivity Effect Nature of
Effect DurationMagnitude(PercentageTraffic Increase)
PotentialSignificance Summary of Mitigation Residual Effect Residual
SignificanceChangefrom 2012Chapter
Impact onpedestrians, cyclistsand public transport.Road safety anddriver delay
Increase in dailylight vehiclemovements
Duringconstruction
Increase in localtraffic Minor Adverse
Implementation of aConstruction Site SafetyPlan (CSSM) and a Code ofConstruction Practice(CoCP)
Aim to reduce andmanage the impactfrom the additionalvehicle movements asfar as is possible.
Negligible No change
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12.12 Summary and Conclusions
12.12.1 The methodology adopted in assessing the traffic and transportation effects
of the Development has been detailed within this chapter and undertaken in
line with IEMA guidelines and DfT guidelines. It has also been agreed with
Gwynedd Council through the 2012 ES for the approved scheme and has
been repeated for comment in the Scoping Report submitted on the 5th
January 2015 for Development.
12.12.2 The assessment of traffic effects for the Development considers the
construction period and operational phase. The findings of the assessments
demonstrate that all traffic can be accommodated on the local road network
without compromising traffic operations.
12.12.3 This chapter has assessed the significance of the effects caused by the
construction phase of the Development. Where there are seen to be
significant effects, mitigation measures have been outlined to minimise,
where possible, the effect of the construction phase.
12.12.4 This chapter outlines that the Development will result in an increase in
traffic volume on the surrounding network. However mitigation measures
have been identified to reduce the potential traffic effect.
12.12.5 The Development accords with the relevant local, regional and national
planning policy guidance in that it is accessible by a range of modes other
than the private car and provides improvements to access the site by a
range of sustainable modes. Associated Travel Plan documentation will
also assist in complying with the relevant guidance by encouraging use of
alternative modes to minimise single occupancy car trips to the site.
12.12.6 It is concluded that residual traffic effects from the construction and
operation of the Development are not significant.
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12.13 References
Guidance on Transport Assessment (Department for Transport) – March 2007
Institute of Environmental Management and Assessment’s (IEMA) ‘Guidelines for
the Environmental Assessment of Road Traffic’ – January 1993
Guidelines for Providing Journeys on Foot (Institution of Highways and
Transportation) – May 2000
Manual for Streets, DfT – March 2007
Planning Policy Wales – 2014
Technical Advice Note 18: Transport