Circle Line MRT service adjustments in early 2026: What you need to know

SINGAPORE – Users of the Circle Line (CCL) will face additional waiting times of up to 30 minutes during peak hours

due to tunnel strengthening works

from Jan 17 to April 19, 2026.

Steel reinforcement plates will be installed for a 450m stretch of tunnels connecting Mountbatten, Dakota and Paya Lebar stations that have shown some signs of deterioration, such as water leaks.

To facilitate this, the two tunnels connecting these stations will be closed one at a time during the three months.

About 480,000 passengers are expected to be affected daily. If you are one of them, here is what you need to know.

Q: How will CCL train service change?

A: Wait times on the entire CCL will be longer during the three months.

Shuttle trains will ply the stretch between Mountbatten, Dakota and Paya Lebar stations, operating at 10-minute intervals from a single platform at these stations due to the tunnel closure.

Trains on the rest of the CCL will turn around at Paya Lebar and Mountbatten stations.

When that single platform is occupied by a shuttle train, incoming trains must wait for it to depart before they can turn around. This waiting process will have an impact on the whole CCL, resulting in longer intervals between trains.

At the 20 stations between HarbourFront and Paya Lebar, peak-hour train frequency will fall, from the current two minutes to about three minutes.

There will be a longer wait of 10 minutes between trains from Mountbatten towards the Dhoby Ghaut or Marina Bay stations, up from six minutes now.

The Land Transport Authority (LTA) has said that passengers may want to avoid the stretch between Mountbatten and Paya Lebar, and use other bus and rail connections instead.

Q: Will shuttle bus services be available?

A: Shuttle bus services will start on Jan 5, so that passengers can familiarise themselves with alternative travel routes, LTA said.

Services will ply routes between several stations on the CCL during weekday peak hours to ferry passengers to stations not affected by the works. These services will follow the same fare structures as the trains.

Services during the morning peak:

Services during the evening peak:

Q: What if I want to stick to trains?

A: If you are travelling during the morning and evening peak periods, it may be faster and more convenient to travel on other MRT routes to avoid crowded stretches on the CCL.

For example, passengers travelling from the north-east region on the North East Line (NEL) to one-north, Kent Ridge or Buona Vista can transfer to the Circle Line at HarbourFront, instead of making the transfer at Serangoon.

This journey from Serangoon to one-north would take about 45 minutes. The same journey on the CCL would take about 58 minutes, factoring in the longer waiting time and crowded trains.

Those travelling from the north-east to Buona Vista and farther west towards Clementi and Tuas Link should take the NEL to Outram Park station, where they can transfer to the East-West Line (EWL) to Buona Vista and westwards, towards Tuas.

The journey from Serangoon to Clementi during the weekday peak period on the NEL and EWL is expected to take about 47 minutes, compared with about 65 minutes on the CCL, where the intervals will be longer.

LTA said passengers should expect CCL interchange stations, such as Bishan, Serangoon and Buona Vista, to be crowded during the morning and evening peaks.

“During these periods, additional waiting time could extend to up to 30 minutes compared with typical travel times,” LTA said.

During the evening peak period, passengers boarding at Tai Seng and Bartley stations, which tend to have a higher volume of passengers, will have to wait longer to get on trains.

Passengers at Tai Seng and Bartley are advised to take the CCL to Paya Lebar and transfer to the EWL to Buona Vista and beyond. The estimated travel time between Tai Seng and Buona Vista stations is 47 minutes using the CCL and EWL, versus 61 minutes on the CCL.

For those travelling outside the morning and evening peak periods, the crowd situation is expected to be manageable, even with longer intervals between train arrivals throughout the day.

Q: Why must these tunnel reinforcement works be done?

A: The tunnels were built on soft marine clay, which gradually compresses and can cause the circular tunnel to become more elliptical – or oval-shaped – with the passage of time. This process is known as “tunnel squatting”.

Associate Professor Raymond Ong, from the Department of Civil and Environmental Engineering at the National University of Singapore, said tunnel squatting can lead to structural defects in the tunnel if left unaddressed. These can include the leakage of water through joints and the deterioration of concrete.

LTA said there were already minor defects in tunnels affected by tunnel squatting, such as signs of water leakage, which were fixed by using grouting to seal the leaks. Grouting is a construction method that entails filling voids or cracks with a dense fluid mixture.

Professor Chu Jian, chair of the School of Civil and Environmental Engineering at Nanyang Technological University, said tunnel squatting, if unaddressed, may lead to severe disruptions that will have a worse impact on passengers than a planned three-month service adjustment.

“If it is left untreated, it may lead to a much bigger scale of repair, or even... affect the safety of the MRT operation,” Prof Chu said.

Mr David Ng, chairman of the civil and structural engineering technical committee at the Institution of Engineers, Singapore, said MRT tunnels have been designed to last 120 years.

“This repair is designed to strengthen the tunnel... to last for its original design life of 120 years under these soft marine clay conditions,” he said.

Mr Ng added that it is unlikely the same stretch of tunnel will require more repairs in the future.

Q: Is the CCL still safe?

A: Yes, the CCL remains safe to use, and consultants engaged by LTA have confirmed that train operations can continue safely while the strengthening works are carried out.

Q: Why put passengers through this inconvenience?

A: The installation of steel plates requires heavy equipment, specialised machinery and multiple work teams, LTA said.

More than 300 workers and engineers will be deployed, supported by engineering wagons and locomotives equipped with robotic arms and cranes.

Because of the scale and complexity of the works, extended engineering hours are needed, and LTA opted to close the tunnels in turn, so that works can be carried out around the clock.

It is a complicated process as workers must ensure that the live components of the railway systems are not inadvertently damaged, said Prof Ong.

Mr Ng said it is impractical for the works to be done during regular engineering hours, which last three to four hours a night.

He added that the tunnel works should be carried out when the defects are still minor. Otherwise, “the deformation might become worse, and (the) structural capacity of the tunnel lining will be affected”, he said.

Prof Ong said that if the tunnel works were to be carried out during regular engineering hours, a huge amount of time would be wasted on logistics, such as the movement of people and heavy equipment in and out of the tunnels. This would lead to the repairs taking much longer.

He said the key challenges of this work will be related to logistics, as heavy machinery and hundreds of workers need to move from entry points, such as depots, to the locations where the repair is to be done.

Prof Chu said working underground in “very congested areas with many buildings above and utilities nearby in the ground” also has its challenges. “The space available for operation is very limited, and any operation has to ensure that (any) effect on the adjacent buildings or facilities (is) kept to the minimum,” he said.

Prof Ong said the three-month expected duration for the tunnel works “is well within the range of expectation”, given the complexity of the tasks at hand.

“We need to adopt the understanding that such repairs are required for the longevity of the system,” he said.