Start-up nuTonomy has resumed trials of driverless cars after a traffic accident involving one of its vehicles on Oct 18.
The company has improved its software system after an investigation into the accident, it said yesterday.
One of nuTonomy's self-driving cars hit a lorry in Biopolis Drive at one-north while on a test drive at about 9.30am on Oct 18.
It is believed to be the first accident in Singapore involving an autonomous vehicle.
No one was hurt. However, the right bumper of the car was damaged.
The lorry had a dent on its side, according to a Facebook user who posted photos of the accident.
The self-driving car had two engineers on board and one was behind the wheel as a safety driver, nuTonomy said in an earlier statement. It added that its car was travelling at a "low speed".
nuTonomy found that the accident was due to "an extremely rare combination of software anomalies".
This affected how the vehicle detected and responded to other nearby 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," nuTonomy said.
After the changes and tests, the United States-Singapore firm resumed public trials on the roads in one-north recently, it added.
It said such fixes demonstrate the value of "conducting extensive testing".
"The ongoing public trial of nuTonomy's self-driving cars continues to provide us and our partner, Grab, with valuable feedback, data and insights from a growing number of riders," it noted.
Thousands of people have signed up online to participate in the trial since August.
"The majority of passengers quickly accept and grow comfortable with the technology during their rides," nuTonomy said.
One of the findings from the trials was that passengers "humanise" the car, by giving it a name or compare its driving ability to that of a relative or friend.
nuTonomy is one of four agencies permitted by the Land Transport Authority (LTA) to conduct trials of driverless vehicles in the one-north area.
The other three are A*Star, Delphi and Singapore-MIT Alliance for Research and Technology.
The LTA has also signed partnership agreements with nuTonomy and Britain-based Delphi to test self-driving taxis in Singapore.
nuTonomy targets to have a limited commercial service by 2018 with up to 75 vehicles available in certain areas, with services rolled out islandwide by 2020, said reports.
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