Train Service Reliability Transparency, please

In Minister Lui's parliamentary reply on 9 July 2013, he stated that there were a total of 32 major incidents, that exceeded 30 minutes of service disruption in the period between January 2010 and June 2013. Of these, 17 were on the North-South-East-West Line (NSEWL); nine on the Circle Line (CCL) and six on the North East Line (NEL). The majority of these incidents seems to have occurred in the years 2010 - 2011 because LTA Chief Executive Mr Chew Hock Yong said that there were only three incidents in 2012 that exceeded 30 minutes of service disruption, in a separate media update in May 2013.

However, our data shows otherwise. Between January 2010 and June 2013, there were 93 incidents exceeding 30 minutes of service disruption on the NSEWL, CCL and NEL combined. Adding the numbers for Bukit Panjang LRT and Punggol LRT, there were a total of 101 incidents. Even if a stricter criteria is set, there were a total of 63 incidents that disrupted service for at least one hour. The figure reported in Parliament seems to be understated. Will the authorities put up the list of 32 major incidents for public scrutiny?

Total Bukit Panjang LRT Circle Line East West Line North East Line North South Line Punggol LRT
Number of Service Disruptions Exceeding 30 Minutes 101 7 14 41 9 29 1
Number of Service Disruptions Exceeding 60 Minutes 63 5 9 21 7 20 1

As the same parliamentary reply did not provide a breakdown of service disruptions by the cause of delay, we will attempt to do so using our own dataset:

The following table shows the details of service disruptions that exceeded 30 minutes in duration:

In their regular press releases, the LTA-SMRT and LTA-SBS Transit Joint Teams like to 'normalize' the data by reporting the steadily declining ratio of train service disruptions to the total number of train-kilometres operated. While such metrics may be relevant (and look good!) to management, commuters are impacted by the number of service disruptions, not the number of train-kilometres operated. Besides, this metric cannot decisively conclude that the situation is improving when the number of train-kilometres operated has been increasing over the years, thereby lowering the ratio artificially. It is a well-known PR technique to gloss over a piece of bad news (number of service disruptions) with red herrings as distraction. In this case, the red herring is the number of train-kilometres operated, which the authorities know for a fact, that it will be increasing in the foreseeable future due to the surge in passenger demand and expansion of the rail network and train fleet. It is too hasty to claim credit on the basis of a single metric. Transparency is the key to rebuilding the trust lost.

Train Faults Halved?

Contrary to the LTA-SMRT Joint Team's glowing report that train faults have been halved on the North-South-East-West lines (NSEWL), our data shows that there has not been any significant reduction in the number of service disruptions nor delay hours over the same period (June - August 2012). The December report continued the happy chorus, announcing that the train withdrawal rate was reduced from 3.2 (per 100,000 km) in 2011 to 2.6 in the second half of 2012. Notice how they have deliberately left out the data in the first half of 2012, which saw 3.91 trains withdrawn (per 100,000 km) from January through April 2012.


  • The second half of 2012 saw a higher frequency of service disruptions on the NSEWL, with the worst month in October.
  • The LTA-SMRT Joint Team congratulated itself in September for having 'significantly reduced' train withdrawals in just three months of work. Despite this improvement, the impact to commuters has actually worsened as June and August saw longer delay-hours than May.
  • System Service Availability (SSA) is an Operating Performance Standard (OPS) stipulated by the Land Transport Authority (LTA). Failure to comply with the OPS can subject the service operators to fines by LTA.
    • The East-West Line failed to meet the 99.5% SSA for 6 months in 2012 (January, February, April, May, June and October).
    • The North-South Line failed to meet the 99.5% SSA for 2 months in 2012 (April and October).
    • The Circle Line failed to meet the 99.5% SSA for 1 month in 2012 (October).

If the LTA-SMRT Joint Team wishes to convince the public that train services have become more reliable, they should be more transparent. The train withdrawal rate is only a single metric and being a lead KPI, it may not result in real improvements to commuter experience on the ground. If the LTA-SMRT Joint Team is truly confident in their performance, it should publish lag KPIs, such as the monthly SSA figures for each rail line.