Waymo, the autonomous car unit of Google holding company Alphabet Inc, will begin test-driving self-driving Chrysler Pacifica minivans later this month on public roads in Arizona and California, CEO John Krafcik said.

At the AutoMobili-D exhibit at the North American International Auto Show in Detroit on Sunday, Krafcik said Waymo's "mission is to make it safe for people to move around".

Krafcik said Waymo is developing advanced sensor technology that will make self-driving vehicles safe for use in just about all conditions. He noted that Waymo has reduced the cost of Lidar, which scans for obstacles by about 90 percent from its $75,000 level of a few years ago.