(Reuters) – U.S. supermarket operator Kroger Co said it will start testing driverless grocery delivery on Thursday with technology partner Nuro at a single Fry’s Food Store in Scottsdale, Arizona.

Kroger and rival Walmart Inc each have teamed up with autonomous vehicle companies in a bid to lower the high cost of “last-mile” deliveries to customer doorsteps, as online retailer Amazon.com rolls out free Whole Foods delivery for subscribers to its Prime perks program.

“Kroger wants to bring more customers the convenience of affordable grocery delivery,” said Kroger Chief Digital Officer Yael Cosset, who added that the test will also gauge consumer demand for the service.

The first phase of the test will use a fleet of Toyota Prius cars equipped with Nuro technology. Those cars have seats for humans who can override autonomous systems in the event of an error or emergency. Nuro’s R1 driverless delivery van, which has no seats, will begin testing this autumn, the companies said.

“While we compete final certification and testing of the R1, the Prius will be delivering groceries and helping us improve the overall service,” a Nuro spokeswoman said.

Self-driving car delivery from the Fry’s store will cost $5.95 with no minimum order. It is only available at addresses within the store’s zip code of 85257, Kroger said.

Walmart and Alphabet Inc’s self-driving car company Waymo are partnering to test a service that shuttles Phoenix shoppers to stores to collect online grocery orders.

(Reporting by Lisa Baertlein in Los Angeles, Editing by Rosalba O’Brien)