The Land Transport Authority (LTA) said it will avoid testing new trains during off-service hours on Sunday nights, following a disruption on the North-East Line (NEL) on Monday morning.

This is to minimise the impact on passenger service during the morning peak hour the next day, should a fault occur. On Monday, 41,000 NEL commuters, were hit by a disruption of about two hours, after a test train had pulled a wire on the line's overhead power system during off-service hours, causing a power fault.

The LTA said that, moving forward, it will "adopt a risk-based approach" in developing the testing schedule for new trains.

Transport Minister Khaw Boon Wan said LTA explained to him that testing was not a daily affair and was done progressively - first during engineering, or off-service, hours over weekends, then during off-peak hours and, finally, when ready, into peak-hour traffic.

"Since breakdowns cannot be completely eliminated, we must be prepared for Murphy's Law and expect the worst," said Mr. Khaw. "Even when things are tried and tested, we must anticipate and buffer for further glitches and failures, so we do not let the stress of something unplanned happen during stressful events, like our children's national examination."