PHOENIX (AP) — Google's self-driving vehicle division says it's bringing autonomous trucks to the Phoenix area.

Waymo announced Wednesday that its self-driving tractor-trailers will start driving on freeways this week and will expand to more routes over time.

Waymo's self-driving passenger vehicles are ubiquitous in the eastern Phoenix and its suburbs, where the company conducts extensive testing and runs a taxi service.

The company says the big trucks use the same sensors as passenger vehicles but they're configured differently. The testing will start with two drivers in each truck.

Companies including Uber and TuSimple have driven self-driving trucks on Arizona roads. Waymo says it tested trucks in Arizona in 2017.

Waymo and Google are both subsidiaries of Alphabet Inc., based in Mountain View, California.