The new North-South Line signalling system will be tested all day on Sundays starting from April 16.
The tests - which are expected to last two months - will replace the current trials on weekdays, which began on March 28. The weekday testing, during the last hour of service from Monday to Thursday at 11pm, will end tonight.
Train operator SMRT and the Land Transport Authority (LTA) said yesterday that passengers should not feel any difference in their journeys during the tests.
It added that the progressive roll-out will allow for issues to be addressed as soon as they are discovered, minimising inconvenience to commuters.
One of the issues found during the weekday tests was a "software bug" where train doors remained closed at the stations. Under the new system, train doors should open automatically.
SMRT and LTA said this issue and others will be "progressively corrected" over the course of the trial.
The results of the trial will help to determine when the new system - which will allow trains to run faster at intervals of 100 seconds instead of 120 seconds currently - will be fully implemented.
About one-third of delays of more than five minutes last year on the 30-year-old North-South and East-West lines were signal-related, SMRT said last December.
Changing the tests to make them full-day operations allows for better testing of issues such as train scheduling and fleet management, said Singapore Institute of Technology assistant professor Zhou Yi, a chartered railway engineer.
The upgraded signalling will also allow for the addition of 57 new trains, the first of which will begin operations on Sunday, as part of plans to increase capacity on the two oldest lines.
In addition to being fitted with the new signalling system, the new trains will also have a number of new features, such as LCD displays. Besides showing upcoming stops, the displays will also show the locations of exits at the next station as well as nearby attractions.
LTA's rail systems director Yee Boon Cheow said that the new trains have been put through "rigorous tests".
