Google's self-driving car project, now called Waymo, made some big strides during 2016, according to a report from the company published by the California Department of Motor Vehicles.
California requires would-be self-driving car manufacturers to apply to the state's autonomous vehicle testing program and submit regular reports if they want to test their cars on public roads in the state. Several companies participate, including major car brands, suppliers, and hopefuls. Waymo has been submitting reports since at least 2015.
The report published Wednesday lists the number of times a driver had to take over for the autonomous system while driving — these are known as disengagements. Waymo's total number of disengagements per 1,000 miles of driving went from 0.8 in 2015 to 0.2 in 2016 — a precipitous drop.
Most of these disengagements are not accidents, but they often represent times when a driver would have had to shut the system down to make some kind of fix. The drop in disengages shows that drivers need to interrupt the system less often — in other words, the company is refining the technology.