Google on Sunday unveiled ahead of the Detroit auto show its latest self-driving system in a Chrysler Pacifica minivan, saying the technology is more reliable and affordable.

The announcement came from John Krafcik, head of Google's Waymo unit.

Last month, Waymo and Fiat Chrysler announced the production of the initial 100 minivans, vehicles equipped with the technology developed by Waymo, the new Alphabet company formed from its Google car project.

Krafcik said Waymo's latest set of self-driving hardware and software incorporated a new array of sensors, including an enhanced vision system, improved radar and laser-based lidar, all developed and built in-house.

He added that Waymo had reduced the cost of a single lidar unit by 90 percent, to about $7,500.

Waymo plans to test the first self-driving Pacificas this month on public roads in California and Arizona. Krafcik did not say when the system would be ready to install in production vehicles.

Waymo has been seeking for partners to develop and install its autonomous driving technology into cars has. The company has yielded an alliance with Fiat Chrysler Automobiles and a has also announced a pending deal with Honda Motor Co.

Waymo's existing test fleet of self-driving cars, including some specially equipped Lexus RX450s and Google's own "Firefly" prototypes, has accumulated nearly 2.5 million miles in less than eight years, mostly on city streets.

Delphi Automotive Plc and Mobileye NV have said they are collaborating on a self-driving system that could be sold to automakers beginning in 2019.

Ford Motor, General Motors and BMW AG have said they intend to introduce self-driving cars in 2021.