How do we formulate the railway alignment?

When planning and designing the railway alignment, we have carefully studied and considered multiple factors while consulting stakeholders in a timely manner. We hope the new railway will serve the needs of the existing and future communities, while promoting sustainable development.

The factors we need to take into account during the formulation of the railway alignment include:

Planning and land development

  • To be in line with the overall distribution and growth of the local population
  • To align with the existing and future land and housing development potential and needs, such as the new town development planned by the Government, as well as the transport needs incurred, with the aim to suitably integrate and create synergy between railway planning and land development, thereby facilitating the long-term sustainable development of Hong Kong

Land requirements

  • To consider the development requirements of the land along the railway alignment and to avoid the alignment from passing through private lots wherever practicable, with the principle of preventing the resumption of private lands, buildings and strata as far as possible to minimise the potential impacts of railway development on residents and the nearby communities

Environment and construction techniques

  • To consider the potential impacts of the locations of railway facilities, relevant construction works, and operations on the surrounding environment and communities, including landscape and ecology, while adopting a sustainable design for the proposed railway facilities to better integrate into the neighbouring communities and minimise the possible impacts on stakeholders
  • To avoid country parks and conservation areas
  • To minimise the potential impacts on the above-ground land and public facilities as far as possible
  • To consider the topography and geology of the area when determining the constructability, engineering considerations on construction techniques, predictability of construction time of building railway facilities in different scheme options, as well as decide on the tunnel building and construction methods per the geological conditions and geographical environment

Railway Operations and Development

  • To comply with the design standards of railway tunnels, for example, avoiding steep tunnels and sharp curvature to ensure the safety of the railway tunnel and the buildings along the alignment
  • To ensure sufficient space is reserved for constructing various railway ancillary facilities, which is essential to railway operation and emergency rescue purposes, such as ventilation buildings, depots, and emergency access and egress points, etc.
  • To take into consideration the implications of each alignment option on the future potential railway extensions, railway operations and maintenance

Transportation needs

  • To complement the transportation needs of the existing and future residents, as well as the road traffic conditions in the area
  • To serve the long-term needs of transportation and its related facilities to enhance the overall transportation network of the city

How do we decide between above-ground and underground scheme options?

As for the above-ground or underground scheme options, both have their relative pros and cons, for example:

Scheme option / Factors in determining the scheme

Above-ground

Underground

Engineering considerations on understanding of geological conditions

Vary in different situations

Engineering considerations on construction techniques

Vary in different situations

Predictability of construction time

Relatively higher

Relatively lower

Impact on use and development of above-ground lands

Relatively more

Relatively less

Impact on environment, including surrounding ecology, especially for ecologically important sites

Relatively long-term

Relatively short-term

After preliminary technical assessment and consideration of various factors, including the opinions of different stakeholders, it is proposed to adopt an underground railway alignment for the Northern Link to minimise the potential impacts on the nearby environment and ecology during construction and operation, as well as provide more flexibility for the future planning and development of the nearby land along the railway alignment.