(Reuters) - Amazon.com’s self-driving car unit, Zoox, is seeking to stay abreast of rival Waymo by expanding its vehicles’ testing in California and Nevada to include a wider area, higher speeds and nighttime driving.

The changes, announced on Thursday, apply to Zoox's fleet of vehicles that it designed and built itself. Those resemble toaster ovens on wheels and lack manual controls inside, like steering wheels, pedals and gear shifters. Zoox also operates retrofitted self-driving Toyota Highlanders in Seattle, Las Vegas, San Francisco and Foster City, California.