North-South Corridor delayed two years: Viaduct openings start in 2029, tunnels in 2031

Singapore’s North-South Corridor (NSC) has a revised opening schedule after difficult ground conditions complicated excavation and foundation work. Its viaduct is now expected to open in phases from 2029, followed by its tunnel in phases from 2031—each about two years later than previously announced. Those years mark the start of staged openings, not a promise that the entire corridor will be ready at once. 215

When will the viaduct and tunnel open?

The viaduct from Admiralty Road West to Lentor Avenue is expected to open in phases from 2029, rather than 2027. The tunnel from Lentor Avenue to the East Coast Parkway is expected to open in phases from 2031, rather than 2029. 215

Work is still advancing: as of August 2026, LTA said more than 90% of foundation works had been completed for both the viaduct and tunnel sections. Viaduct construction had moved on to above-ground structures, while major excavation continued along the tunnel alignment. Foundation progress, however, is not the same as an opening date. 3

What caused the delay?

The obstacles differ by location, but they share a practical consequence: crews have had to work more carefully through ground that proved harder to build in than anticipated, often close to roads or operating rail infrastructure. 421

• Novena: At the crossing of the operational North–South MRT Line, the southbound NSC tunnel above the rail line was completed using a tunnel-box-pushing method. Excavation for the northbound tunnel below it then encountered fractured rock and groundwater inflows that could not be fully identified in advance. LTA adopted excavation in smaller, separately supported sections to manage those conditions safely. 4
• Thomson: Hard rock, large boulders and groundwater complicated excavation, requiring changes to construction methods and slowing progress. 1819
• Woodlands: Around Gambas Avenue and Woodlands Avenue 8, utility diversions and adverse ground conditions prolonged piling and pile-cap work for the viaduct. 4

What happens to roads, footpaths and cycling connections in the meantime?

LTA expects travel conditions to improve progressively as major surface-level structural work finishes. Roads, footpaths and adjacent areas occupied by construction are expected to be reinstated for public use in stages from 2028; restoration in more technically challenging stretches is expected from 2030. That is a separate timetable from the viaduct and tunnel openings. 325

The longer-term plan is to divert more vehicle traffic onto the viaduct and into the tunnel, then repurpose surface streets for wider footpaths, cycling paths, bus priority measures and public space. These changes will also be introduced progressively. The available updates do not give a reopening date for every affected pedestrian or cycling connection, so residents, businesses and commuters should not assume that all local routes will return when the first road section opens. 525