LCQ20: Improvement of the Lion Rock Tunnel

Following is a question by the Hon Dominic Lee and a written reply by the Secretary for Transport and Logistics, Mr Lam Sai-hung, in the Legislative Council today (November 16):

Question:

The Government has pointed out that as the Lion Rock Tunnel (LRT) has shown signs of deterioration in its structure and LRT also needs a greater capacity to cope with the traffic demands during peak hours and in the future, the Government has proposed to carry out the Improvement of Lion Rock Tunnel (Improvement Project) which is anticipated to commence in the first quarter of 2025 and complete in 2034. In this connection, will the Government inform this Council:

(1) as there are views pointing out that the construction period of the Improvement Project is too long, whether the Government has studied construction methods which can expedite the project's completion, so as to reduce the dust and noise generated by the project as well as the impacts on nearby residents; during the period when the Improvement Project is being carried out, whether a number of bus routes and public light bus routes passing through LRT will be affected, as well as whether the Government will put in place more measures to alleviate the traffic congestion problem of LRT;

(2) as some residents of the housing courts near LRT (e.g. Hill Paramount, Parc Royale, Fung Shing Court, World-Wide Gardens and Julimount Garden) are worried that the traffic noise problem following the completion of the Improvement Project will become more serious due to the increase in traffic volume, whether the Government has assessed if the installation of noise barriers along the relevant road sections can effectively mitigate the noise; if it has assessed and the outcome is in the affirmative, of the details; if the assessment outcome is in the negative, of the measures in place to ensure that the existing traffic noise problem of such housing courts will not become more serious after the completion of the Improvement Project;

(3) whether it has assessed the capacity of LRT upon the completion of the Improvement Project, and if such capacity can resolve the traffic congestion problem of the tunnel and reduce the traffic load of adjacent roads; if it has, of the details; if not, the reasons for that;

(4) as it has been reported that the Improvement Project will cause impacts of varied degrees on the environment near LRT (e.g. about 0.16 hectare of woodland and 0.17 hectare of plantation in Lion Rock Country Park will be permanently affected), of the remedial measures the Government has in place to alleviate the impacts of the Improvement Project on the environment; and

(5) whether it has plans to develop the existing northbound tunnel tube of LRT into a pedestrianised street or a pathway for pedestrians and cyclists upon the completion of the tube's rehabilitation works, so as to let nearby residents have one more commuting choice; if so, of the details; if not, the reasons for that?

Reply:

President,

On the various parts asked by Hon Dominic Lee, having consulted the Highways Department and Transport Department, the reply is as follows:

(1) The Government gazetted the Improvement of Lion Rock Tunnel project on October 14, 2022 and targets to commence its detailed design next year. Subject to comments from the public received during the gazettal period and the progress of the detailed design, we will strive to commence the works in 2025.

The Lion Rock Tunnel is a major road connecting the New Territories and Kowloon. In order to maintain the normal operation of the tunnel, the tunnel improvement works need to be carried out in stages. The project first requires the construction of a new tunnel tube between the two operating road tunnels, in very confined works area with much site constraint. At the same time, existing facilities (including ventilation buildings, administration building) will need to be relocated and reprovisioned to free up areas for the works while maintaining normal tunnel operation. After the completion of the new tunnel, it is also necessary to re-direct traffic amongst tunnel tubes a few times for carrying out the expansion works for the existing tunnel tubes. Reprovisioning, testing and commissioning of the electrical and mechanical systems as well as fire services installations, which are essential to tunnel operation, are also required before each diversion and take time to complete.

In addition, due to the heavy traffic at Lion Rock Tunnel and its connecting roads, some works such as the installation of noise barriers/noise enclosures, can only be carried out under temporary road closure during non-peak hours. The project also requires the reprovisioning of the existing major fresh water mains located inside the tunnel tubes. These major water mains supply fresh water to many areas in both Kowloon and Hong Kong Island. It is expected that such reprovisioning works will involve extensive changes to the fresh water supply zones and have to be carried out in stages to maintain a stable fresh water supply. All in all, the project is complex and very challenging, and will need to be carried out with great caution.

It is now expected that the new tunnel tube can be commissioned four years after the commencement of works, and the tunnel will be able to cater for dual three-lane traffic another four years after that. The Highways Department will adopt "Early Contractor Involvement" by inviting contractors to provide input based on past experience during the design stage of the project to optimise the designs and construction planning of the project. The Department will also continue to explore the application of innovative designs with a view to expediting project implementation. During construction, we will also implement mitigation measures and an environmental monitoring and audit programme to control dust and noise, amongst others, according to the recommendations of the Environmental Impact Assessment (EIA) report to reduce the impact of the works on the nearby environment.

As mentioned above, the tunnel improvement works will be carried out in stages to maintain the number of existing traffic lanes during peak hours. The Government will also formulate suitable temporary traffic arrangements for the construction, and will maintain close liaison with relevant stakeholders during the construction period to ensure that the impact of the construction on the existing traffic and public transport services be minimised.

The Government will continue to monitor the road traffic condition, review and implement appropriate measures to ease the traffic in the New Territories East. At present, the Civil Engineering and Development Department is taking forward the Widening of Tai Po Road (Sha Tin Section) project, which is expected to be completed in 2023. In addition, the Trunk Road T4 in Sha Tin was gazetted on November 26, 2021 and targets to seek funding approval from the Legislative Council for commencing the construction works in 2023 after completion of the necessary statutory procedures and design work. Upon their completion, the projects are expected to help alleviate the traffic condition in Sha Tin and the surrounding areas.

(2) Regarding traffic noise, the Highways Department has conducted an EIA for the project in accordance with the requirements of the Environmental Impact Assessment Ordinance (EIAO) (Cap. 499) and the EIA Study Brief (Study Brief). The relevant EIA report has been submitted to the Environmental Protection Department (EPD) for approval. The EIA report has examined the details of the project and assessed the potential impact, such as noise, on sensitive receivers within the assessment area (such as nearby housing estates), having regard to the characteristics of the surrounding environment. Based on the EIA result, the Highways Department has formulated appropriate mitigation measures, including the proposed installation of noise barriers/noise enclosures along some sections of the Lion Rock Tunnel Road to improve noise level and ensure that the project complies with the requirements of the EIAO.

(3) The Lion Rock Tunnel currently provides for dual two-lane traffic and will be upgraded to provide dual three-lane traffic after completion of the project. The capacity of each tunnel tube will be increased from 3 600 passenger car units per hour (pcu/hr) (note: passenger car unit per hour (pcu/hr) is a unit for measuring traffic flow in equivalent number of private cars as design basis. For example, a pcu value of 1.0 is assigned to private cars and taxis. Heavy vehicles such as goods vehicles or buses which usually travel at a lower speed are assigned higher pcu values.) to 5 400 pcu/hr. It is expected that upon completion of the project, it will be able to meet the anticipated traffic need brought by future developments, enhance the connectivity between the New Territories and urban areas, as well as improve the traffic condition along Sha Tin and Kowloon.

(4) The Highways Department has conducted an EIA on the project in accordance with the requirements of the EIAO and the Study Brief, which covers the ecological impact of the project (including on the woodland and plantation areas within the Lion Rock Country Park). The EIA report has been submitted to the EPD for approval. HyD will implement mitigation measures in accordance with the recommendations of the EIA report, such as planting at suitable locations near the works areas to compensate for the woodland loss, to mitigate the environmental impact of the project.

(5) The proposal of opening up the existing northbound tunnel tube for use by cyclists and pedestrians will not only affect the prompt opening of the northbound tunnel for emergency vehicular use if needed, various considerations such as the supporting network and facilities near the Kowloon and Sha Tin portals of the Lion Rock Tunnel, relevant fire safety requirements and safety escape, technical constraints, cost-effectiveness also have to be taken into account. We will thoroughly explore the feasibility of the proposal, including actively engaging relevant stakeholders, and at the same time continue to discuss with relevant bureaux and departments on the optimal use and arrangement of the tunnel tube.

Ends/Wednesday, November 16, 2022
Issued at HKT 14:55