Google’s Waymo self driving car project is proving to be much more effective on the roads than rival Tesla.

According to data filed with the California department of motor vehicles, in 2016 Waymo cars required far fewer disengagements than Tesla.

Disengagements refer to instances of the autonomous system being deactivated and control handed back to the passenger, usually due to system failure or road situations that require human control.

In 2016, Waymo logged over 600,000 autonomous miles in California and reported just 124 disengagements whereas the Tesla Autonomous Vehicle Program drove only 550 miles and reported 182 disengagements. This means that for every 1,000 miles Waymo disengaged 0.2 times compared to 330 times by Tesla.

Gartner analyst Mike Ramsey told CNBC: “This is just more evidence of the gulf between Waymo and all other companies in terms of testing and execution of self-driving systems.”

Google currently boasts an impressive number of 60 self driving cars and their decision to increase miles travelled by 50% has seen disengagements fall from to 0.8 times per 1,000 miles in 2015 to 0.2 times in 2016.

In a blog post, Dmitri Dolgo, Head of Waymo’s self driving car technology said: “In the last few years we’ve amassed over 2.5 million miles of autonomous driving on public roads. We’ve taught our cars to handle some of the most complex driving tasks (e.g. navigating construction zones), and how to interact with other drivers (e.g. merging into a lane during rush hour).”

Other companies also made huge leaps in testing autonomous cars, General Motors reported it’s Cruise had driven over 9,000 miles with an average 18.5 disengagements per 1,000 miles, Nissan logged 4,000 with 6.8, and Delphi achieved a 3,000 and 57 all, over a 12 month period.

In late 2016 Tesla CEO, Elon Musk, announced plans to improve Tesla Inc. automated driving technology through the use of vision systems and new sensors.

Waymo began testing new sensors last month and has reportedly been in talks to share it’s autonomous tech with Honda.