SINGAPORE - The first week of

scheduled disruptions to the Circle Line (CCL)

saw around 30,000 passengers turn to peak-period shuttle bus services, set up to ease congestion as trains run at reduced frequencies.

An average of 480,000 passengers are affected each day by the disruptions, which are necessary to carry out tunnel strengthening works from Jan 18 to April 19. These works affect the CCL’s Mountbatten, Dakota and Paya Lebar stations.

Four weekday shuttle bus services, which run during the peak hours, began operations on Jan 5 ahead of the disruptions to help travellers familiarise themselves with the arrangements. These services follow the same fare structures as the trains.

Senior Minister of State for Transport Sun Xueling said on Jan 28 that travel times have increased by around 10 to 20 minutes. Some commuters have also changed their routes - for instance, using the North East Line (NEL) instead of the CCL.

Ms Sun, who was speaking to reporters at a tentage outside Serangoon MRT station where passengers were waiting to board the shuttle buses, said that as travellers become more familiar with the arrangements, the number of marshals and volunteers deployed to manage crowds will be reduced.

Her comment came after a Forum letter to The Straits Times on Jan 27 said that the large number of crowd marshals deployed have added to congestion during peak periods. The Land Transport Authority (LTA) said on Jan 13 that about 500 additional ground staff will be working daily to direct commuters during the service adjustment period.

Ms Sun also gave an update on tunnel strengthening works, saying that around 10 per cent of the work is done and the project is on track to be completed by April 2026.

The works, which will take nearly three months to complete, is one of the longest scheduled MRT service disruptions yet.

They affect three sectors of CCL tunnels between the Stadium and Paya Lebar stations, with a total length of around 450m. The LTA has found that in these parts of the tunnels, which are built in soft marine clay, a phenomenon known as tunnel squatting has occurred. These are deformations, which needs to be addressed to prevent disruptions in train operations and structural defects in the tunnel.

Strengthening works involve closing each tunnel in turn at the affected sectors to put in steel plates along the circumference of the affected tunnel segments. The LTA has said that train operations can continue safely during this period.

Ms Sun also said that some commuters have changed their travel timings to make use of the free morning off-peak train rides on the NEL and the enhanced Travel Smart Journeys where travellers get rebates if they take qualifying bus services.

Lee Nian Tjoe is senior transport correspondent at The Straits Times, where he also oversees the Motoring section.