Rail operator SMRT Corp and regulator Land Transport Authority are deciding what to do with the problematic Bukit Panjang LRT (BPLRT) system and may even scrap it altogether.
In a company blog, SMRT Trains managing director Lee Ling Wee said a joint team is reassessing the future of the system, with a view to giving it a major overhaul.
"It will be more than just a makeover," Mr Lee wrote, adding that the 17-year-old system is near the end of its design life, referring to the lifespan of a system before extensive renewal.
He said there are three options.
One, deploy self-powered autonomous guided vehicles on the existing viaduct. Earlier this year, SMRT announced a venture to market, supply and operate the Netherlands-based 2getthere's automated vehicles here and in the region.
Two, build a new LRT system with significant design enhancements. Mr Lee noted that the current system is more suitable as an airport shuttle plying short distances on flat ground.
Three, renew the existing Bombardier system with an updated signalling system, allowing trains to be tracked more accurately and to ply at a higher frequency.
If the three options are not feasible, there is another: scrapping the LRT and going back to buses.
"This is not far-fetched, as a fully-loaded high-capacity bus like a double-decker can take 130 passengers, which is more than the 105-person capacity of a single Bombardier train," he said, but added that this option would of course lead to more road congestion.
The LTA, however, said that "replacing the light rail system with an all-bus option is not likely to be practical, given road capacity".
Meanwhile, Mr Lee added that SMRT engineers have proposed short-term measures to boost the reliability of the system. Repair and maintenance efforts are also being stepped up.
These include replacing its rail brackets, load-testing trains to reduce power faults, adjust motor controller settings, and install cameras on the undercarriage of four train cars to monitor the interface between trains and rail.
The BPLRT has been beset with problems since it began operating in 1999, most recently last week, when services were disrupted for more than eight hours.
Mr Lee noted that because of reliability issues, staff trained to manually operate a stalled train have had to be deployed at stations. This, he said, means the unmanned system is not living up to its name.
Bukit Panjang resident Ashley Wu, 35, said: "I've always felt the LRT brought more inconveniences than conveniences to us. The feeder buses worked much better.
"But, of course, I recognise that traffic situatons today are different after 17 years."
SIM University senior lecturer Park Byung Joon said doing away with the line should be considered, noting that there are a few successful implementations of such a system at airports and parks, but not as public transport for the masses.
Mr Rajan Krishnan, chief executive of engineering firm KTC group, said he favours the first two options of transforming the system. The third, he said, was "tricky".
"I don't think it's going to be much cheaper than getting a new LRT system," he said.
National University of Singapore transport researcher Lee Der-Horng said: "Ideally, an LRT system should integrate with a town's design... but the BPLRT was not quite like that (it was built after the town was there).
"That's probably one of the reasons it has had a bumpy journey from Day One."