SINGAPORE: The Land Transport Authority (LTA) is upgrading its bus Estimated Time of Arrival (ETA) system as part of measures to minimise a repeat of last month’s disruption, Acting Minister for Transport Jeffrey Siow said on Wednesday (May 6).
Inaccurate bus timings and long wait times were displayed at bus stops and on transport apps on Apr 18 after fibre network cables were damaged during construction works for the North-South Corridor project.
The damaged cables also caused a nearly 20-hour broadband service outage, affecting about 5,000 users in Ang Mo Kio, Bishan, Sengkang and Punggol.
Responding to questions in parliament from MP He Ting Ru (WP-Sengkang) and MP Mariam Jaafar (PAP-Sembawang), Mr Siow said the new ETA system, which will be deployed by the end of 2027, will be hosted on a cloud platform.
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“This will improve the resilience of the ETA system against physical damage to its data connections,” said Mr Siow.
He said that the current ETA system relies on physical fibre-optic connections to relay updates on bus locations to a central server, which then computes predictions of bus arrival times.
“For data security reasons, bus location data is transmitted through dedicated pairs of fibre-optic cables that are privately leased from a commercial vendor,” said Mr Siow.
“By design, if data cannot be sent through one cable, it will be rerouted to the other cable, so that the connection continues to function.
“This provides a backup against physical damage.”
On Apr 18, Asia Piling Co, a sub-contractor carrying out contiguous bored piling works for the North–South Corridor project, damaged several fibre-optic cables, of which one was part of a physical connection transmitting to the ETA server.
“As designed, data was diverted from the damaged cable to the intact cable in that connection pair,” said Mr Siow.
“However, not all data was successfully sent to the server when the incident first occurred. This resulted in a degradation of the ETA system performance, with only 70 per cent of the expected number of ETA predictions throughout the rest of the day.”
The ETA system was restored to full functionality after the fibre-optic cable was repaired, he said, adding that LTA’s investigation revealed no other hardware or software malfunctions in the ETA system.
Mr Siow said that LTA is still investigating why the remaining intact cable did not provide full redundancy for the damaged cable, as required of the vendor.
Should Asia Piling be found culpable for damaging the fibre network cables, agencies may take legal action and telecommunication companies may also claim damages.
“Contractors are required to comply with the requirements of the relevant utility agencies when working in proximity to their services. For instance, prior to work commencement, contractors must conduct utility mapping and obtain written approval from the utility agencies,” said Mr Siow.
“Land Transport Authority enforces against noncompliance, which are factored into future tender evaluations.”
April’s disruption to LTA’s bus ETA system came months after a separate issue in January this year, when a "memory cache build-up" in on-board systems prevented buses from transmitting their location data to the central server, causing inaccurate bus timings to be displayed.
Mr Siow said on Wednesday that last month’s disruption had no relation to January’s incident.
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Inaccurate bus timings and long wait times were displayed at bus stops and on transport apps on Apr 18 after fibre network cables were damaged during construction works for the North-South Corridor project.
The damaged cables also caused a nearly 20-hour broadband service outage, affecting about 5,000 users in Ang Mo Kio, Bishan, Sengkang and Punggol.
Responding to questions in parliament from MP He Ting Ru (WP-Sengkang) and MP Mariam Jaafar (PAP-Sembawang), Mr Siow said the new ETA system, which will be deployed by the end of 2027, will be hosted on a cloud platform.
CNA Games
Show More Show Less
“This will improve the resilience of the ETA system against physical damage to its data connections,” said Mr Siow.
He said that the current ETA system relies on physical fibre-optic connections to relay updates on bus locations to a central server, which then computes predictions of bus arrival times.
“For data security reasons, bus location data is transmitted through dedicated pairs of fibre-optic cables that are privately leased from a commercial vendor,” said Mr Siow.
“By design, if data cannot be sent through one cable, it will be rerouted to the other cable, so that the connection continues to function.
“This provides a backup against physical damage.”
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On Apr 18, Asia Piling Co, a sub-contractor carrying out contiguous bored piling works for the North–South Corridor project, damaged several fibre-optic cables, of which one was part of a physical connection transmitting to the ETA server.
“As designed, data was diverted from the damaged cable to the intact cable in that connection pair,” said Mr Siow.
“However, not all data was successfully sent to the server when the incident first occurred. This resulted in a degradation of the ETA system performance, with only 70 per cent of the expected number of ETA predictions throughout the rest of the day.”
The ETA system was restored to full functionality after the fibre-optic cable was repaired, he said, adding that LTA’s investigation revealed no other hardware or software malfunctions in the ETA system.
Mr Siow said that LTA is still investigating why the remaining intact cable did not provide full redundancy for the damaged cable, as required of the vendor.
Should Asia Piling be found culpable for damaging the fibre network cables, agencies may take legal action and telecommunication companies may also claim damages.
“Contractors are required to comply with the requirements of the relevant utility agencies when working in proximity to their services. For instance, prior to work commencement, contractors must conduct utility mapping and obtain written approval from the utility agencies,” said Mr Siow.
“Land Transport Authority enforces against noncompliance, which are factored into future tender evaluations.”
April’s disruption to LTA’s bus ETA system came months after a separate issue in January this year, when a "memory cache build-up" in on-board systems prevented buses from transmitting their location data to the central server, causing inaccurate bus timings to be displayed.
Mr Siow said on Wednesday that last month’s disruption had no relation to January’s incident.
Continue reading...