Waymo's vehicles drove 2 million miles in self-driving mode across 25 cities in 2017, putting its total autonomous miles to 4 million. It accelerated its testing to prepare for its
ride-hailing fleet's launch this year, allowing it to "gather as much data as possible in order to improve [its] technology." According to its
annual report submitted to the government of California, Waymo drove 352,545 of those miles in The Golden State from December 2016 to November 2017. Within that period, the company reported a total of 63 disengagements (instances wherein the human test driver had to step in), which means its vehicles drove an average of 5,595 miles for every disengagement.