North-South Corridor delayed by two years, will open in phases from 2029 - CNA

Unexpectedly challenging ground conditions have required more complex construction methods and set back the timeline, the Land Transport Authority says.

The North-South Corridor construction site at Novena on Sep 15, 2026. (Photo: CNA/Ili Mansor)

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Justin Ong Guang-Xi 17 Sep 2026 05:00PM (Updated: 17 Sep 2026 05:53PM) Bookmark Bookmark Share WhatsApp Telegram Facebook Twitter Email LinkedIn Set CNA as your preferred source on Google Add CNA as a trusted source to help Google better understand and surface our content in search results. Read a summary of this article on FAST. Get bite-sized news via a newcards interface. Give it a try. Click here to return to FAST Tap here to return to FAST FAST SINGAPORE: The opening of the North-South Corridor has been delayed by two years due to unexpectedly challenging ground conditions, the Land Transport Authority (LTA) said on Thursday (Sep 17).

The viaduct section, from Admiralty Road West to Lentor Avenue, is now expected to open in phases from 2029, instead of 2027 as previously announced.

The tunnel section, from Lentor Avenue to East Coast Parkway (ECP), is now expected to open in phases from 2031, instead of 2029.

Commuters and motorists along the corridor can expect travel conditions to improve as major structural works are completed, LTA said. Roads, footpaths and other adjacent areas occupied by construction will be progressively reinstated for public use from 2028.

CNA Games Guess Word Crack the word, one row at a time Buzzword Create words using the given letters Mini Sudoku Tiny puzzle, mighty brain teaser Mini Crossword Small grid, big challenge Word Search Spot as many words as you can Show More Show Less For more technically challenging stretches, such as around Thomson Road near the Pan Island Expressway (PIE) interchange where major tunnel works remain ongoing, reinstatement is expected to take place from 2030, it said. 

LTA added that it will continue to review progress and restore affected areas for public use as soon as it is safe and practicable to do so.

“This means that as works are completed, construction disamenities can be reduced when spaces along the corridor are progressively reinstated ahead of the North-South Corridor's opening,” it said.

The agency said earlier this month that construction was entering its “most technically demanding” phase.

Spanning more than 20km, the corridor is a multi-modal transport link designed to improve connectivity between the northern region and the city, serving towns such as Sembawang, Yishun, Ang Mo Kio, Toa Payoh, Novena and Rochor while relieving traffic along Singapore’s north-south transport axis.

The project comprises two major structures: an 8.8km elevated viaduct and a 12.3km underground tunnel section.

Construction has been ongoing since 2018 and LTA previously said the corridor would open in stages from 2027.

LTA highlighted three work sites where challenges have delayed the construction timeline.

At Novena, the corridor's tunnels intersect with the North-South Line MRT tunnels.

Due to space constraints, the corridor's southbound tunnel runs above the MRT tunnels and its northbound tunnel below. 

The southbound tunnel has been completed. But work on the northbound tunnel ran into unexpected fractured rock and groundwater inflows.

As a result, a more precise and time-intensive mining method was adopted, with excavation carried out in smaller sections instead of using the direct tunnelling method originally planned.

The fractured rock was also found along the lower half of the northbound tunnel, requiring the work to proceed in two phases. 

Tunnelling through the softer ground in the upper half began last month and is expected to be completed by the end of this year. Excavation of the lower half will begin in 2027 and continue through 2028, using controlled blasting.

LTA said the revised approach takes longer as workers have to remove rock, carry out grouting and install supports as excavation advances, but this was necessary to prevent soil movement or settlement that would have affected MRT operations and traffic in Novena.

Site investigations also found harder-than-expected rock formations where the tunnels were to be built. 

Rock volume equivalent to seven Olympic-sized swimming pools was encountered and had to be excavated. In addition, tunnel diaphragm wall works that would have typically taken a week to build now take up to a month.

For the viaduct section at Gambas Avenue and Woodlands Avenue 8, harder and higher rock levels meant some piles had to be driven deeper than planned.

Asked why such challenging ground conditions were not detected before construction began, LTA said extensive investigations and engineering studies were carried out during the planning, design and construction stages. 

"However, underground conditions can vary significantly over short distances, and it is not possible to fully characterise every part of a long and complex underground corridor before construction begins," it said.

This is particularly difficult in a densely built-up environment like Thomson Road and Novena, where investigations have to be carried out around live traffic, existing utilities, structures and operational MRT infrastructure. 

"Closing the full traffic corridor to carry out additional investigations would have caused significant disruption and was not feasible. Some investigations therefore had to be carried out progressively as access and space became available during construction."

Construction of the North-South Corridor has led to multiple traffic diversions and mitigation measures such as noise barriers in areas such as Novena, Bugis, Ang Mo Kio, Marymount and Woodlands.

From 2027, works will progressively move underground, and residents and businesses can expect a gradual reduction in construction noise.

From 2028, surface streets will be reinstated in the interim, with roads and footpaths completed in stretches and noise barriers removed. 

From 2029, commuter connectivity will be improved, with cycling paths implemented in phases and pedestrian overhead bridges reinstated.

LTA said it will continue to deploy additional manpower and equipment where effective, and will optimise construction sequences and prioritise critical activities to make up time where feasible. 

It added that it will keep residents, businesses and other stakeholders updated on upcoming works and traffic arrangements.

“We recognise that the revised timeline will prolong construction impact for residents, businesses, motorists and commuters along the North-South Corridor, and appreciate the public’s patience and support as we work through these challenges,” said LTA.