Cross Island Line

Connecting across the island

Map of Cross Island Line Phase 1

Our eighth MRT line, the Cross Island Line (CRL) will be our longest fully underground line at more than 50 kilometres long. It will serve existing and future developments in the eastern, western, and north-eastern corridors, connecting major hubs such as Jurong Lake District, Punggol Digital District and Changi region.

When operational, it will have the highest number of interchange stations, with almost half the stations on the line being linked to existing rail stations. This means more alternative travel routes to get to your destination.

Constructed in three phases, the 29km long Phase 1 of the CRL (CRL1) will comprise 12 stations from Aviation Park to Bright Hill. This will serve residential and industrial areas such as Loyang, Tampines, Pasir Ris, Defu, Hougang, Serangoon North and Ang Mo Kio. More than 100,000 households will benefit from CRL1, and common recreational spaces such as Changi Beach Park and Bishan-Ang Mo Kio Park will also become accessible by public transport. Construction for CRL1 is expected to commence in 2020 and be completed by 2030.

In light of COVID-19-induced factors such as a general manpower crunch due to border closures and materials supply disruptions, the completion timelines for a number of LTA projects have been delayed up to a year. The revised rail completion and opening timelines are being finalised and updates will be issued in due course.

To bring greater accessibility and better rail connectivity across the island, we will be building the Cross Island Line (CRL) – Punggol Extension, which connects Pasir Ris to Punggol. The 7.3-kilometres extension will provide a direct link for commuters travelling between eastern areas such as Pasir Ris and Tampines North and north-eastern areas such as Punggol and Sengkang.

The Punggol extension will consist of four fully-underground stations namely Punggol, Riviera, Elias and Pasir Ris.

Three of the four stations are interchanges, which will shorten travel times and provide alternative travel options for commuters.

After in-depth studies of both alignment options, the Government has decided to adopt direct alignment for the stretch of the Cross Island Line in the vicinity of the Central Catchment Nature Reserve (CCNR). In reaching this decision, the Government has considered various factors, including the concerns expressed by all stakeholders and the findings of the comprehensive two-phased Environmental Impact Assessment (EIA). The reports for the two EIA phases were shared with the public in 2016 and 2019 respectively.

Nature Groups, a key stakeholder LTA engaged and sought valuable inputs from throughout the planning process, have also shared their collective response to EIA Phase 2.

Alignment Options for CRL

To allow an informed decision on the alignment for the stretch of the Cross Island Line in the vicinity of CCNR to be made by the government, LTA had appointed an internationally-acclaimed consultant to conduct a comprehensive two-phased EIA and involving multiple stakeholders including the nature groups, heritage groups, residents and grassroots leaders. 

Alignment Option CCNR
Above: Direct (blue line) and Skirting (pink line) alignment options. CCNR boundary marked by black line
Two-phase EIA Process

Phase 1 evaluated the existing ecosystem and physical conditions of the CCNR as well as the environmental impact of site investigation (SI) works within the CCNR.  Phase 1 had been completed with the report gazetted and published on the LTA website in 2016.  The findings of the SI works (carried out following the report) were used to inform Phase 2 of the EIA.

Phase 2 zoomed into the potential environmental impact of the construction and operations of the CRL as well as the required mitigation measures.  LTA sought inputs from, and engaged with, the relevant stakeholders as part of this process.  This phase of the EIA has recently been completed and a comprehensive report on its findings was published. Extensive consultations are being held to consider all views and issues, including the environmental impact, length of commute, engineering feasibility, disruptions to businesses and families, as well as the cost to taxpayers. 

LTA gazetted the EIA Phase 2 report on 2 September 2019 and made it available for public views for one month from the gazette date. We thank the public for your feedback.

Figure 7_small
direct alignment option
  • 2km tunnel beneath the CCNR, 2km outside it
  • Approximately 70m deep or the height of a 25-storeys HDB flat
  • Tunneling will be done fully in hard granite rock
  • No physical structure on the surface level within the CCNR
skirting alignment option
  • Does not cross under the CCNR, skirts around (and away) from CCNR
  • Approximately 45m deep to ensure that tunneling will be safe for buildings and away from existing underground infrastructure along this alignment
  • 9km tunnel route length under roads as well as residential and commercial buildings
  • About 6 minutes less commuting time under the direct alignment between any two CRL stations on either sides of the CCNR.
  • About 15% less per trip for commuter fare on average under the direct alignment.
  • Estimated daily ridership of more than 600,000 across the whole CRL in the initial years, and over one million in the longer term, under the direct alignment. This will be lower under the skirting alignment as some commuters are expected to remain on the existing lines.
EIA Phase 2 Report for Cross Island Line CCNR Alignment Options

Engineering Schemes 

LTA have devised robust engineering schemes for the two alignments.  These schemes define the geographical focus and construction techniques to be adopted that informed the EIA.  The engineering schemes are robust and independently reviewed by LTA’s International Panel of Advisors (IPA)[1].  The IPA comprises internationally renowned experts in geotechnical and tunnel engineering, who concluded that with control measures in place, tunnelling along either alignment option is safe.

The EIA, by Environmental Resource Management (S) Pte Ltd (ERM), was rigorously undertaken based on an internationally-recognised framework and relevant authoritative references[2].  ERM is a global specialist in environmental, social, health, safety and risk management consulting services that have done similar EIA works in the UK, China and Hong Kong.  The EIA Report, too, was independently reviewed by an appointed consultant[3].

Key points of Phase 2 EIA Report
  • The EIA was commissioned by LTA, and conducted by ERM, to aid decision-making on the alignment options as part of a rigorous process of understanding the environmental impact.
  • Based on the EIA, both underground alignments are feasible. The residual impacts for the factors studied are largely moderate or below. Moderate impact indicates small effects that are around existing conditions and/or within accepted standards.
  • All EIA impacts are largely confined to the worksites outside the CCNR and the tunnel alignments that run deep underground beneath the CCNR (for the direct alignment option) or around it (for the skirting alignment option).
  • LTA is committed to undertake all necessary mitigation measures to minimise potential environmental impact.

[1] The members to the IPA are appointed on a two-yearly basis by LTA. For the 2017-2019 term, the IPA was chaired by Prof Yong Kwet Yew (Singapore), NUS Senior Vice President and Professor of Civil Engineering, whilst the other IPA members included Mr John Busbridge from Canada, Ex-President Golder Associates on Global Operations; Mr Eddie Woods from the United Kingdom, Tunnel Discipline Lead for UK High Speed 2 and ex-Chief Engineer Thames Tideway Tunnel; Prof Lee In-Mo from Korea University, Director of Institute of Underground Space Technology and ex-President of International Tunnelling Association; Mr Tadashi Hashimoto from the Director of Geo-Research Institute in Japan and Overseas Expert of Science and Technology committee to Shanghai Municipal Commission.

[2] The biodiversity assessment for the CRL Phase 2 EIA Report took into account the international standards set out in the International Finance Corporation (IFC) Performance Standard/Biodiversity Offsets and accompanying materials.

[3] Mr. Tony O'Dempsey was engaged by LTA as the independent reviewer for the EIA (Phase 2) Report. He was also the independent environmental consultant in Phase 1 site investigation works inside the CCNR. Tony has been working as a volunteer on various conservation projects relating to the Nature Reserves for the past 20 years and is very familiar with the forest habitats of the CCNR. An active member in the Nature Society of Singapore (NSS), he has held various positions in the past, including council member of NSS and chair of its vertebrate study group. He is a professional who has been working in the Geographic Information System (GIS) industry in Singapore for 25 years and has applied his GIS and cartography skills to the various conservation projects he has worked on.  He has a Bachelor Applied Science (Surveying) from Queensland University of Technology. 

No. of stations icon

Number of stations

Length of rail line icon

Length of line

Expected project completion icon

Expected completion

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