The Bukit Panjang LRT network will be closed every Sunday for 11 weeks, starting on April 15, as part of maintenance works to improve the reliability of the beleaguered system.
Rail operator SMRT yesterday said 30 shuttle buses, running parallel to the LRT network, will be deployed during the closures.
The works that will take place include replacing sections of the power rail and track switch components.
Mr Roger Lim, vice-president for SMRT's Circle Line and Bukit Panjang LRT, said: "More intensive maintenance works, such as the replacement of sections of the power rails, are not possible with the short two-to three-hour engineering window between services."
Closing the network on Sundays will allow these works to be completed sooner, he added.
Speaking to the media, Land Transport Authority (LTA) chief executive Ngien Hoon Ping said full-day Sunday closures could extend beyond June if more maintenance work needs to be done, but said commuters would be notified of such closures ahead of time.
Some residents said the closures may result in some inconvenience for them. Civil servant Chew Lihong, 27, said she takes the LRT almost daily from her home near Keat Hong station to Bukit Panjang, where she gets on the Downtown Line.
"Buses just don't cut it, because the journey would take much longer," she said.
The maintenance works are separate from the overhauling of the LRT system that will be undertaken by supplier Bombardier, which built the Bukit Panjang LRT.
LTA and Bombardier yesterday signed a $344.25 million contract for these renewal works - expected to be completed by 2024.
The renewal works include replacing the signalling system and 19 first-generation LRT trains.
The issue of dislodged collector shoes - which draw electricity from the rails - will also be addressed by measures such as installing stronger new rail brackets.
In 2015, a dislodged collector shoe resulted in a 1 1/2 hour breakdown affecting 10,000 commuters.
In a Facebook post yesterday, Transport Minister Khaw Boon Wan, who witnessed the signing of the contract, said: "Bukit Panjang residents can certainly look forward to more reliable LRT rides when most of the renewal works are completed by 2022."
He also challenged SMRT to ensure that the Bukit Panjang LRT - which he said was facing "obsolescence" after 19 years of operation - closes the gap with the more reliable Sengkang-Punggol LRT line.
Last year, the Sengkang-Punggol line clocked 115,000km between delays of five minutes. The Bukit Panjang LRT did only 53,000km.