2.1.1 The Project comprises the improvement of the existing Tung Chung Road between Lung Tseng Tau in North Lantau and Cheung Sha in South Lantau. The improved road should connect with the existing road in Lung Tseng Tau in the north and South Lantau Road in the vicinity of Cheung Sha in the south. The location of the “Broad Corridor for Alignment Options” for the Project as given in the Assignment Brief is shown in Figure 1.1.
2.1.2 The scope of the Project as given in the Assignment Brief comprises:
¨ widening or realignment of the existing Tung Chung Road between Lung Tseng Tau and Cheung Sha to a two-lane two-way rural road, approximately 7 km long, with a general carriageway width of 7.3 m and a footpath of about 1.6 m wide (the width depends on the amount of utilities);
¨ a bus to bus interchange with bus bays and U-turn facilities for buses near the junction of Tung Chung Road and South Lantau Road; and
¨ construction of associated bridges, retaining walls, geotechnical works, landscape works, drainage works, utility works, traffic aids, traffic safety enhancement measures, environmental mitigation measures and other ancillary works.
2.1.3 The scope of the Project has been more clearly defined based on the findings of this Assignment. The refined scope of the Project comprises:
¨ widening and realignment of the existing Tung Chung Road between Lung Tseng Tau and Cheung Sha Sheung Tsuen to a two-lane rural road, approximately 6.2 km long, with a general carriageway width of 7.3 m, and a 1.6 m wide grassed verge plus 2.0 m wide paved footway along the widened section and a 1.6 m wide paved verge along the realigned sections;
¨ roadside bus laybys and taxi layby facilities near the new junction of Tung Chung Road and South Lantau Road with a U-turn facility for vehicles travelling along Tung Chung Road; and
¨ construction of associated bridges, retaining walls, geotechnical works, landscape works, drainage works, utility works, traffic aids, traffic safety enhancement measures, environmental mitigation measures and other ancillary works.
2.1.4 The ancillary works for this Project as given in the Assignment Brief include the provision of passing bays, traffic surveillance and road use control measures, slope stabilisation works to natural and manmade slopes, which would affect or be affected by the new road alignment and the existing Tung Chung Road, traffic calming measures, traffic safety enhancement measures, traffic management measures, fire hydrants, street lighting, etc.
2.2.1 The only way to improve the geometry of the existing road, whilst minimising the environmental impacts, is to relax the design standards. Therefore, the Assignment Brief states that:
¨ the design standard of the road gradients may be relaxed at difficult locations, provided, in any case, the maximum gradient of the improved road does not exceed 15%;
¨ the provision of a continuous climbing lane will not be required, but that passing bays should be provided at suitable locations instead; and
¨ where there are practical site difficulties or severe environmental problems, all essential road design criteria such as design speed, vertical and horizontal curvatures, transition curves, visibility, footpath, etc might need to be reviewed, but that the prior agreement from the Director of Highways and the Commissioner for Transport shall be obtained for each case.
2.3.1
Layout
of Proposed Road Improvement
General
2.3.1.1 The proposed road improvement commences at Lung Tseng Tau, and climbs up Tung Chung Valley along the route of the existing road as far as Tai Tung Shan Service Reservoir. South of the reservoir, the proposed road veers east from the existing route, and crosses the small plateau at the head of the valley, before rejoining the existing route at the crest at Pak Kung Au. South of the crest, the new road again veers east from the existing route, and traverses the hillsides around the southern flanks of Sunset Peak, before crossing the catchwater and connecting with South Lantau Road to the east of Cheung Sha Sheung Tsuen. The total length of the new road is about 6.2 km. The general layout of the new road is shown in Figures 2.1 to 2.11.
Northern
On-Line Section (Ch 1,000 to 3,200)
2.3.1.2 The location of the north end of the new road is fixed by the layout of the proposed improvement to Tung Chung Road between Pa Mei and Lung Tseng Tau to be carried out by Territory Development Department (TDD). This section of roadworks is currently programmed to be substantially complete by the commencement of the roadworks between Lung Tseng Tau and Cheung Sha. The layout of the interface between the two respective projects is shown in Figure 2.2.
2.3.1.3 The new road has been designed to follow the existing road from Lung Tseng Tau up to Tai Tung Shan Service Reservoir, since parts of the existing road have already been widened to 6 m and the existing geometry is within the acceptable standards of the Project. Improving the road on-line will have fewer impacts overall and be more economical than going off-line over this section of the route. Indeed, the alignment has been designed such that the road widening works will generally take place on the east side of the existing road, such that during construction, the existing road can be used as a buffer zone to help prevent construction site runoff from entering into the ecologically important Tung Chung Stream. This issue is discussed in detail in Section 6 of the EIA report.
2.3.1.4 From Lung Tseng Tau (Ch 1,000: +11 mPD), the road proceeds across the lower slopes on the east side of Tung Chung Valley above Fong Yuen Marsh up to the junction with Shek Mun Kap Road (Ch 1,750: +32 mPD). Along this section of the route, the road undulates gently between two local high points (Ch 1,430: +31 mPD and Ch 1,630: +36 mPD) and two local low points (Ch 1,540: +30 mPD and Ch 1,840: +30 mPD).
2.3.1.5 South of the junction, the road begins its steady climb up the valley, passing the footpath to Burial Ground No. 18L (Ch 2,340: +61 mPD) and the access road to the Country Park Management Centre (Ch 2,630: +78 mPD), before reaching the reservoir (Ch 3,150: +143 mPD). The maximum gradient over this section of the route is 12.8%.
Northern
Off-Line Section (Ch 3,200 to 4,480)
2.3.1.6 Between Tai Tung Shan Service Reservoir and the crest at Pak Kung Au, the existing road includes gradients above 15% and a number of hairpin bends, which places the existing geometry below the acceptable standards of the Project. Therefore, this section of road can only be improved by going off-line.
2.3.1.7 Over this section of the route, the existing road continues to climb up Tung Chung Valley, and then runs along the western fringe of the small plateau at the head of the valley. However, the plateau is only relatively level along its east-west axis. Along its north-south axis (ie, along the general direction of the route), the gradient of the plateau is greater than 15%. From a geometric point of view, this section of the new road is generally the most difficult section to design. Only by winding the new road across the plateau can gradients of 15% or under be achieved.
2.3.1.8 The alignment of this section of the route has been designed not only to restrict gradients to a maximum of 15%, but also to minimise the length of road with 15% gradient. This is because heavy goods vehicles and buses may encounter problems when trying to restart when travelling in the uphill direction at 15% gradient after coming to a stop or in the event of stalling. Shorter sections of road with 15% gradient are considered less problematic in this regard.
2.3.1.9 The new road goes off-line immediately south of Tai Tung Shan Service Reservoir (Ch 3,200: +150 mPD). The road passes to the east of the existing road in cutting, thereby bypassing three pairs of hairpin bends along the existing road. This section of the new road is the steepest, and the road runs at the maximum acceptable gradient of 15% for a little over 0.7 km. The alignment follows the hillside above the existing road as closely as possible to minimise the size of the cuttings.
2.3.1.10 On the reaching the small plateau (Ch 3,930: +259 mPD), the new road follows a relatively gentle meandering alignment across the plateau, thereby reducing the gradient over much of this section of the road from 15% to 13%. The alignment has been designed to minimise the impacts to the streams running across the small plateau.
2.3.1.11 At the head of the valley, the new road has been designed to rejoin the existing road to pass through the existing cutting at the crest at Pak Kung Au (Ch 4,480: 334 mPD), since the existing road has already been widened to two-lane standard through the cutting.
Southern Off-Line
Section (Ch 4,480 to 7,170)
2.3.1.12 Between the crest and South Lantau Road, the existing road includes gradients as steep as 20% and more hairpin bends, which also places the geometry of this section of existing road below the acceptable standards of the Project. Therefore, this section of road can also only be improved by going off-line.
2.3.1.13 Over this section of the route, the existing road runs down the east side of Cheung Sha Valley, and then crosses over Cheung Sha Stream at the catchwater. The road then runs down the west side of the valley, and connects to South Lantau Road about 50 m west of the bridge across the stream, behind Cheung Sha Beach. The gradients along the existing road are steeper on this side of Lantau Island because the straight‑line distance between the crest and South Lantau Road (about 1.7 km) is significantly shorter than the straight‑line distance between the crest and Lung Tseng Tau (about 3.2 km).
2.3.1.14 The new road has been designed to both overcome the topographical constraints of the existing route, and also avoid the ecologically important Cheung Sha Stream. After passing through the existing cutting at the crest (Ch 4,480: 334 mPD), the new road goes off-line again to the east of the existing road. The new road runs down along the east side of the head of Cheung Sha Valley above the existing road, which in turn runs above the stream. The road then runs around the southern flanks of Sunset Peak and crosses the catchwater (Ch 6,480: +115 mPD) before connecting with South Lantau Road east of Cheung Sha Sheung Tsuen (Ch 7,170: +36 mPD).
2.3.1.15 The topography along the new road is gentler than that along the existing road. As such, the new road is able to fall at a steady gradient of –11% between the crest and the catchwater, and then at –12.3% between the catchwater and South Lantau Road. Furthermore, since the route around the southern flanks of Sunset Peak is relatively smooth, the new road is able to follow the topography closely whilst maintaining a relatively smooth alignment. This route also has the advantage that only about 0.5 km out of the 2.7km long southern section of the new road falls within the catchment of Cheung Sha Stream.
2.3.2
Width
of Proposed Road Improvement
2.3.2.1 The cross-section of the existing road is shown in Figure 2.14. The existing carriageway is generally 4 m wide, but has been widened to 6 m in places. The western verge on the downhill side of the road is generally 1.25 m wide, and contains all the existing services. Many of these services are in a delicate state, and there is little room for any new services. Widening on the eastern side of the existing road therefore has the added benefit of minimising any disturbance to the existing services. There is no verge to speak of on the uphill eastern side of the existing road.
2.3.2.2 The utility authorities have requested to lay a number of new services along Tung Chung Road to provide both new services and enhance existing services to South Lantau. In particular, CLP Power has requested to install new cables along the road, which would eventually replace the existing 33 kV overhead power lines across the hillsides. To accommodate the new services, a 1.6m grassed verge plus 2.0 m wide paved footway will be required along the eastern side of the northern on-line section of the road improvement, as shown in Figure 2.15. The proposed 2.0 m wide footway will tie into TDD’s proposed 2.0 m wide footway alongside the improvement to Tung Chung Road between Pa Mei and Lung Tseng Tau. The new services cannot be accommodated in the widened carriageway, since this will be occupied largely by a special stormwater carrier pipe, which is discussed in detail in Section 6 of the EIA report.
2.3.2.3 It is proposed that the utility authorities lay their proposed new services under the future obsolete sections of the existing road, adjacent to their existing services, to minimise the impacts of the off-line sections of the new road. By doing so, the 2.0 m wide footway may be omitted from the off-line sections of the road improvement, as shown in Figure 2.16. In this respect, pedestrians may use the future obsolete sections of the existing road, which will also be used as a walking trail, as discussed below.
2.3.2.4 Along most of the off-line sections of the new road, the road will be bounded by retaining walls on both the uphill side and the downhill side of the road. To prevent errant vehicles from crashing over the downhill retaining wall a reinforced concrete parapet will be constructed along the top of the retaining wall, as shown in Figure 2.17.
2.3.3.1 The new road will have 21 elevated structures along its length, including the five existing bridges along the on-line section that will be widened to accommodate the new road. Of the 6.2 km length of road, an aggregate length of about 0.5 km will be elevated. The new road has been designed to minimise the amount of elevated structure along the hillside to minimise the visual impacts. However, all the above structures are required to traverse either the larger streams along the route as part of the ecological mitigation or difficult topography. The smaller streams, which generally dry up soon after it has stopped raining, will be placed in culvert under the new road.
2.3.3.2 Most of the structures will comprise single span structures. Furthermore, all the structures have been designed with relatively straight alignments and relatively short span lengths to facilitate the use of prefabricated deck construction, or the use of falsework supported by the abutments and piers for in-situ construction, to avoid disturbing the streams during construction.
2.3.4.1 A considerable length of the new road will be bounded by retaining walls on both the uphill and downhill sides of the road. Indeed, of the 6.2 km length of road, there will be an aggregate length of about 3.0 km of retaining wall on the east side of the road and about 1.8 km of retaining wall on the west side of the road. Retaining walls are proposed to minimise the footprint of the works, and hence the impacts of the new road, by significantly reducing the extent and size of the cut and fill slopes that would otherwise be required.
2.3.5
Junction
with South Lantau Road and Bus-Bay Facilities
2.3.5.1 The proposed junction with South Lantau Road comprises a roundabout. This is not only the recommended junction type for the anticipated traffic movements, but also provides a U-turn facility for vehicles travelling along Tung Chung Road, particularly buses. Bus laybys will be constructed near the new junction for franchised buses, and a taxi stand will also be provided for taxis. Passenger shelters will also be provided along the footways at the bus-bays and taxi stand to shelter people from the weather. Construction of the new junction will require local realignment of South Lantau Road, as shown in Figure 2.11.
2.3.6
Bus
Laybys and Passing Laybys
2.3.6.1 Five pairs of bus laybys will be provided along the new road at the following locations:
¨ at the junction with Shek Mun Kap Road (near Ch 1,600 and 1,700);
¨ at Burial Ground No. 18L (near Ch 2,300 and 2,400);
¨ at the crest at Pak Kung Au (near Ch 4,300 and 4,400);
¨ at the catchwater (near Ch 6,500); and
¨ at the south end of the road near the new junction with South Lantau Road.
2.3.6.2 A pair of bus laybys will also be provided on the realigned section of South Lantau Road to the west of the new junction with South Lantau Road. The existing bus layby on the westbound lane of South Lantau Road opposite the YWCA will also be retained.
2.3.6.3 Passing laybys will also be provided in the uphill direction, to allow slow moving vehicles to pull over and let following vehicles pass, at the following locations:
¨ Southbound Direction: near Ch 3,200, 3,600 and 3,900; and
¨ Northbound Direction: near Ch 5,000, 5,400, 5,900 and 6,900.
2.3.6.4 A general loading and unloading layby will also be provided in the northbound direction at the crest at Pat Kung Au (near Ch 4,500).
2.3.7
Combined
Cycle Track / Maintenance Access Track for Special Stormwater Drainage Pipe
between Lung Tseng Tau and Shek Mun Kap Road
2.3.7.1 A 3.5m wide maintenance access track is required along the route of the proposed special stormwater carrier pipe between Lung Tseng Tau and Shek Mun Kap Road, which is discussed in detail in Section 6 of the EIA report. The maintenance access track will have a dual purpose, since it will also be used as a cycle track, which will link up with TDD’s proposed cycle tracks at Lung Tseng Tau and Shek Mun Kap Road. The layout of the proposed combined cycle track / maintenance access track is shown in Figures 2.2 and 2.3.
2.3.7.2 From Lung Tseng Tau (Ch 1,000), the track will follow the alignment of the carrier pipe along the western side of the new road up to south of Lung Tseng Tau (Ch 1,260). South of this section, the track will veer off-line and follow the carrier pipe along the hillside below the road at a prescribed gradient up to Shek Mun Kap Road (Ch 1,750), thereby avoiding the two local high points discussed above.
2.3.7.3 It should be noted that the operation of TDD’s proposed cycle tracks is not dependent on the provision of the proposed cycle track between Lung Tseng Tau and Shek Mun Kap Road. However, the proposed cycle track will also function as a 3.5 m wide maintenance access track for the carrier pipe, and as such, a track will be required whether or not it is used as a cycle track. It will therefore be sensible to make best use of the track, and use it as a cycle track for most of the time.
2.3.8
Miscellaneous Facilities
2.3.8.1 Some miscellaneous facilities are required to enable the proper functioning of the new road as follows:
¨ a pump house near the crest at Pak Kung Au (Ch 4,400) to boost the pressure of the existing water supply for those fire hydrants at the crest; and
¨ passenger shelters at the bus laybys and also at the taxi stand near the junction with South Lantau Road to provide shelter from the weather.
2.3.8.2 The pump house will comprise a relatively small single-storey building, about 20 m2 in plan. The building will be located behind the southbound bus layby at the crest, such that maintenance vehicles can pull off the road when visiting the pump house. The passenger shelters will likely comprise the Highways Department (HyD) standard tubular steel framed shelter.
2.3.9
Existing
Man-Made Slope Remediation Works
2.3.9.1 The Project includes the upgrading to current standards of all existing geotechnical features (ie, man-made slopes and retaining walls) along the existing Tung Chung Road, including those sections of the existing road that will become obsolete after the opening of the new road. Some of the features along the northern on-line section of the road improvement will be totally demolished by the roadworks, and as such will not require upgrading. However, many of the features will only be partly affected by the roadworks, and will therefore require remedial works to guard against landslip. The remedial works will generally comprise a mixture of soil nailing, regrading and hydroseeding. Certain fill slopes may also require the addition of a toe wall at the bottom of the slope. The geotechnical features that will require upgrading along the northern on-line section of the new road are shown in Figures 2.3 to 2.5, and those that will require upgrading along the future obsolete sections of the existing road are shown in Figures 2.5 to 2.8, 2.12 and 2.13.
2.3.10
Haul
Road and Works Area
2.3.10.1 General access to the site will be made from the existing Tung Chung Road, which is to remain open during construction, and from South Lantau Road. Construction traffic using these roads will be subject to the prevailing permit control in force at the time of construction.
2.3.10.2 Access to the northern on-line section of the new road for construction equipment will generally be made directly from the adjacent section of the existing road. As such, a dedicated haul road will not be required. However, access tracks off the existing road will be required for construction equipment to gain access to the various new retaining walls and cut slopes, although these will fall within the “Limit of the Road Works Area”.
2.3.10.3 Similarly, a dedicated haul road will not be required for the construction of the northern off-line section of the new road. Instead, access to the site will be made via a series of access tracks, which will connect with the existing road in the various locations where the new road adjoins the existing road, and as such, will fall within the “Limit of the Road Works Area”.
2.3.10.4 However, a dedicated haul road will be required during construction to gain access to the southern off-line section of the site and to transport equipment and materials within this section of the site, since the southern off-line section is remote from the existing road. In order to determine the land requirements of the Project and assess the construction impacts, a haul road has been designed for the southern off-line section of the site. The haul road has been designed to follow the alignment of the new road as close as possible to minimise the land requirements and the construction impacts. However, at the bridge sites the haul road must go off-line to bypass the bridge sites and cross the side-valleys. A temporary barrier will be provided on the downhill side of the haul road to prevent errant vehicles from crashing off the haul road.
2.3.10.5 Works areas will be required for site offices, works yards and storage. The works areas have also been selected to minimise the land requirements and the construction impacts. The main works area will be located at Lung Tseng Tau on the bare ground to the west of the existing road. Secondary works areas will be located on the site of the current HyD works area at Pak Kung Au, the flat open space adjacent to the catchwater near the new road crossing and on the site of the new junction with South Lantau Road and adjacent bus-bay and taxi facilities. As such, no significant clearance will be required for the proposed works areas.
2.3.10.6 In addition to the above, working space will be required along the site to allow construction of the works and for temporary site drainage measures. The “Limit of Road Works Area”, which includes the southern off-line haul road, works areas and working space, is shown in Figures 2.2 to 2.13. The habitat loss and environmental impacts detailed in the EIA report have taken account of this limit.
2.3.11
Natural
Slope Stabilisation Works
2.3.11.1 The areas adjacent to the new road comprise mountainous natural terrain, and it will therefore be necessary to ensure that the natural slopes and boulders above the road will not endanger road users. A Natural Terrain Hazard Assessment (NTHA) has been carried out as part of the Geotechnical Assessment for the Assignment. The NTHA identified no deep seated failures or imminent large scale rock falls above the new road, and therefore no large scale slope stabilisation works or clearance of the natural terrain will be required. However, the NTHA has identified the need to mitigate the following potential hazards:
¨ possible rockfalls from the natural slopes along the lower flanks of Sunset Peak (Ch 2,950 to 6,450); and
¨ debris flows along some of the natural drainage channels, including Stream Nos. 1 to 10, 19, 20 and 30.
2.3.11.2 To mitigate against possible rockfall, unstable boulders and sections of rock outcrop will require stabilisation with rock dowels or concrete buttresses, as illustrated in Figure 2.18. These works will extend beyond the “Road Works Area” into the “Slope Stabilisation Works Area”, which will extend some 200 m above the new road. However, as discussed above, clearance of the vegetation from within this area will not be required. The natural slopes above the southern section of the existing road below the new road will also require stabilisation in a similar manner.
2.3.11.3 The extent of the boulder stabilisation works will be relatively limited, with infrequent dowels or buttresses of limited size being the only requirement. Of the 6.2 km length of new road, stabilisation works will only be required along about 3.5 km of road, or about 100 ha of natural slope. Allowing for an average of two areas of boulder stabilisation per hectare, then only about 200 locations will require stabilisation.
2.3.11.4 The installation of rock dowels would require a small drilling rig and compressor. A small working platform, comprising scaffolding tubes and timber planks about 2 m by 2 m in plan, would also be required by each boulder. Similarly, the construction of concrete buttresses would require a small working platform by each boulder. A helicopter will be required to transport the rig and other equipment to and from the boulder sites. The on-site helicopter pickup and drop-off point will be located in the works area at the catchwater, as shown in Figure 2.10.
2.3.11.5 In addition to the above boulder stabilisation works, flexible rockfall barriers may be required along the crest of certain retaining walls and cuttings above the new road. However, since these works will be adjacent to the roadworks, they will be confined to the “Road Works Area”.
2.3.11.6 To mitigate against the debris flows along some of the natural drainage channels, debris traps will be required at the inlets to the cross-road culverts to prevent debris from blocking the culvert or damaging its headwall. Where the natural channels pass under elevated structure, angled wing walls will be used at the abutments to divert the debris flow around the front of the abutments and under the structure. The foundations for the abutments and any intermediate piers will also be designed to resist the lateral loads imposed by the debris flows. The above works will be confined to the “Road Works Area”.
2.3.12
Detailed
Ground Investigation
2.3.12.1 The Geotechnical Assessment for the Assignment has also recommended that a further detailed ground investigation be undertaken during the detailed design phase of the Project. It is anticipated that about 130 boreholes, 30 trial pits and 15 slope strips will be required along the route of the new road and also at the geotechnical features along the future obsolete sections of the existing road.
2.3.12.2 About 65 boreholes will be located on the hillsides above the road, and will therefore require a helicopter to transport the rig and other equipment to and from the borehole sites, in a similar fashion to those boreholes already carried out successfully during the preliminary ground investigation for the Assignment. The on-site helicopter pickup and drop-off point will be located in the works area at the catchwater, as shown in Figure 2.10. The remaining holes will be located nearer to the existing road, and will be accessible by vehicle, with the aid of a small mobile crane.
2.3.13.1 Since the Project falls within the Country Park and the amount of rock excavation is anticipated to be relatively small, blasting will not be permitted for the construction of the cuttings along the new road.
2.4.1 Following the opening of the new road, it is proposed that the obsolete sections of the old road be used as:
¨ an emergency vehicle access and an emergency diversion route in the event of a serious accident on the new road;
¨ a walking trail; and
¨ accommodation for the existing and new services to minimise the impacts of the off-line sections of the new road, as discussed above.
2.5.1 The total project cost will be about HK$925 million (Average Risk Estimate)
2.5.2 Construction is currently programmed to commence in December 2003, or earlier if possible, with a view to competing the new road by December 2006.
2.5.3 Government has been urged by LegCo to expedite the implementation of this project, and in particular to consider ways to shorten the construction period. As such, it is likely that the normal working day will be extended to allow construction from 7:00 am in the morning up to 11:00 pm in the evening, and the working week will be extended to include Sunday and public holiday working over these same hours.
2.6.1 As discussed in Section 1 of the EIA report, the existing Tung Chung Road is currently subject to the Lantau Closed Road (LCR) permit system and the more stringent Tung Chung Road Prohibited Zone (TCRPZ) permit system. The current safe total two-way capacity of the road is about 100 vehicles per hour. Although the capacity of the new road will increase to about 1,000 vehicles per hour, the new alignment still includes relatively steep gradients along most of its length. As such, it is anticipated that the improved road will be operated as a closed road in a similar manner to the existing road to prevent vehicles from the rest of Hong Kong, without LCR permits, from entering South Lantau. Subject to further analysis, the current TCRPZ permit system might also require retention with appropriate modification to manage traffic on the improved road and tightly control its growth.
2.7.1
Construction
Activities
2.7.1.1 The construction activities for the Project can be divided into broad areas, namely roadworks and bridgeworks for the main alignment and activities required for slope stabilisation and slope remediation works. The key construction activities within these broad activities will include:
(i) Roadworks:
- earthworks;
- retaining
wall construction (required for all areas not on structure); and
- pavement
construction.
(ii) Bridgeworks: - foundation
construction; and
-
deck
construction.
(iii) Slope Stabilisation - soil
nailing/rock dowelling; and
-
equipment
transportation.
(iv) Slope Remediation - earthworks; and
- soil/rock nailing.
(v) Noise Mitigation - foundation construction; and
- erection.
2.7.1.2 The above activities present the key construction activities which have been identified as the basis of the detailed environmental assessment. The schedules of typical construction equipment required for the key activities highlighted above and used the basis for the construction air and noise assessments are detailed in Section 2 of the EIA report.
Table 2.1 Traffic
Figures Assumed for EIA (vehicles/hour)
|
Road Name |
Year 2006(4) |
Year 2021 |
||
|
Peak Hour Traffic Flows (Two Way) |
Percentage of Heavy Vehicles(1) |
Peak Hour Traffic Flows (Two Way) |
Percentage of Heavy Vehicles(1) |
|
|
Tung Chung Road South (Shek Mun Kap Road – South Lantau Road) |
180 |
34 |
1000(2) |
27 |
|
Tung Chung Road North (Road D2 – Shek Mun Kap Road) |
170 |
25 |
1060 |
26 |
|
Road L15 (Road P2 – Road L13) |
50 |
47 |
190 |
26 |
|
Road L7 (Road P2 – Road L13) |
570 |
19 |
670 |
23 |
|
Road D2 (Road P2 – Tung Chung Road) |
250 |
24 |
1140 |
28 |
|
Road P2 (Road D2 – Shun Tung Road) |
1920 |
16 |
2810 |
22 |
|
South Lantau Road East (Tung Chung Road – Mui Wo) |
180 |
37 |
840 |
30 |
|
|
|
|
|
|
|
South Lantau Road West (Tung Chung Road – Tai O) |
110 |
58 |
480 |
29 |
(1)
The
percentage of heavy vehicles assumed for the noise modelling has been made in
accordance with the definition of greater than 1525kg as defined in Calculation
of Road Traffic Noise (CRTN), Department of Transport, UK, 1988.
(2)
Traffic flow
is bounded by the capacity of the 650pcu/hr for Tung Chung Road Southbound.
(3)
Speed limit
50km/h for all roads.
(4)
Prevailing
figures would be with TCRPZ permit system in place.