An accident involving one of its self-driving cars at business park one-north last month was caused by an "extremely rare combination of software anomalies", said start-up nuTonomy in a statement to the media yesterday.
On Oct 18, one of nuTonomy's driverless cars, which had two safety engineers on board, collided with a lorry in Biopolis Drive in what is believed to be the first accident in Singapore involving an autonomous vehicle.
No one was injured in the accident.
We've made improvements to our software system to eliminate these anomalies, and have extensively tested it both in simulation and on private roads to ensure that our vehicles will operate safely going forward.
A NUTONOMY SPOKESMAN
The start-up said the software glitches affected how the vehicle detected and responded to other vehicles when changing lanes.
"We've made improvements to our software system to eliminate these anomalies and have extensively tested it both in simulation and on private roads to ensure that our vehicles will operate safely going forward," said a nuTonomy spokesman.
"Detecting and then fixing this issue is an example of the value of conducting extensive testing of nuTonomy's autonomous vehicle software system."
In its statement, the start-up added that it has recently resumed trials of its vehicles in one-north. The trials were put on hold following the accident.
The Land Transport Authority (LTA) said investigations into the accident were "mostly completed", and that nuTonomy had "cooperated fully" with the LTA and the Traffic Police in their investigations.
The LTA added: "We have been assured of nuTonomy's safety measures and improvements to its software, and are aware that nuTonomy has recently resumed trial activities on public roads."
However, National University of Singapore transport researcher Lee Der Horng said the accident showed that Singapore may need to be more cautious in its move towards the adoption of driverless technology.
"We are moving very fast," he said, adding that it might be better for trials to take place in a controlled environment rather than on public roads.
nuTonomy is one of four agencies currently conducting trials of self- driving cars in the one-north area, earmarked by the authorities last year as a test site for such vehicles.
It has been testing its autonomous vehicles there since April this year. In August, it became one of two firms to sign an agreement with the LTA to conduct trials of on-demand driverless taxi services here, which it began offering to selected members of the public later that month.
nuTonomy said "thousands of individuals" have signed up for the trial on its website since then.
It is expected to begin offering commercial services in selected parts of Singapore in 2018, when it will have a fleet of 75 driverless vehicles here.
The start-up is also slated to begin testing its autonomous Renault Zoes in Boston in the United States, where it has another office, by the end of the year.