The number of disengagements that have happened in Waymo self-driving cars (that being the number of times a human had to take over the controls from the autonomous system) has plummeted since 2015, the tech company has revealed.
In a letter written to the California Department of Motor Vehicles, Waymo said it has experienced 0.2 disengagements per 1,000 miles driven in its autonomous cars in 2016, down from 0.8 disengagements per 1,000 miles in 2015.
The letter noted that Waymo had traveled 635,868 miles on public roads in California in 2016 and experienced just 124 disengagements. In 2015, the tech company;s self-driving cars covered 424,331 miles and experienced 342 disengagements.
A disengagement may happen in an autonomous vehicle for a variety of reasons. With Waymo’s technology, the most commons cause of disengagements were software discrepancies. Unwanted manoeuvres accounted the second most amount, while an engineers’ possible perception of software discrepancy accounted for the third most. Other reasons for disengagements include the presence of emergency vehicles or reckless drivers on the road and changing weather conditions.
Fiat Chrysler announced it had partnered with Google’s autonomous vehicle offshoot Waymo last year. Waymo took delivery of 100 Chrysler Pacifica hybrid minivans in late 2016 and has since gone about fitting the vans with the proper hardware and softare to enable autonomous operation. The vehicles are being tested on public roads in California and Arizona.