If you rely heavily on the Circle Line (CCL) to get to and from work on weekdays, you'll probably want to factor in more travelling time for yourself come January next year.
The LTA has announced that from 17 January to 19 April 2026, essential tunnel strengthening works along the the two tunnels connecting Mountbatten, Dakota and Paya Lebar stations could see commuters facing additional waiting times of up to 30 minutes during peak hours.
The longer commutes are expected because each of the two tunnels running along the three stations will be closed one at a time during the aforementioned period. The tunnel that remains open will then see the deployment of shuttle trains between Paya Lebar and Mountbatten, at intervals of 10 minutes.
In anticipation of the inconvenience that the strengthening works will cause, the LTA will operate new shuttle bus services during weekday peak periods to bring commuters to unaffected parts of the train network.
These will commence on 5 January 2026 - approximately two weeks before the tunnel closure - to give commuters some time to familiarise themselves with their new travel routes, with the services to follow the same fare structures as the trains.
| Bus service number | Bus service type | Service timings | Average intervals |
| 38 | Shuttle bus service between Paya Lebar and Stadium | 06:30am to 09:30am, 05:00pm to 08:00pm | Six to 10 minutes |
| 37A | One-way shuttle bus service from Serangoon to Tai Seng, Macpherson and Paya Lebar | 07:00am to 09:00am | Three to five minutes |
| 37B | One-way shuttle bus service from Tai Seng to Bishan | 05:30pm to 07:30pm | Three to five minutes |
| 37C | One-way shuttle bus service from Tai Seng to Serangoon | 05:30pm to 07:30pm | Three to five minutes |
In addition to these supplementary services, the LTA is also encouraging commuters to explore routes along other MRT lines during the affected period.
Specifically, residents in the North-East who need to travel to the western region of Singapore are encouraged to take the North East Line (NEL) all the way to Outram Park interchange, rather than transfer to the CCL at Serangoon.
They are also encouraged to transit via Harbourfront interchange, rather than Serangoon, if they need to travel to one-north, Kent Ridge, or Buona Vista stations.
The LTA has shared that the latest tunnel strengthening works are necessary in order to protect the CCL against a phenomenon known as 'tunnel squatting', which could potentially lead to structural defects in the long term if left unaddressed.
Caused by the soft marine clay in which some CCL tunnels are built, the phenomenon is apparently a common one (experienced in places such as Shanghai, Taipei and Busan), with counteractive strengthening works requiring heavy machinery and the deployment of several work teams for the installation of steel plates along the circumference of affected tunnel segments.
This, in turn, necessitates longer blocks of engineering hours for the strengthening works to be carried out safely and effectively. In addition to the cities mentioned above, best practices from Barcelona and Lisbon were also studied to map out the impending works along the CCL.
To further remind commuters of the upcoming service adjustments, the LTA will conduct roadshows and engage affected commuters at selected CCL stations in advance. The authority has also directed commuters to its MyTransport.SG mobile app and social media platforms for more details.
