After working through a pilot program in August, the Kroger Co. said on Tuesday that it has started using autonomous vehicles for grocery delivery in Scottsdale, Arizona.

The program is part of a partnership with Nuro, which provides use of its Nuro R1 custom unmanned vehicles. The vehicles use public roads and can only be used to transport goods.

The company said delivery via the Nuro R1s would be available at its Fry's Food Stores. There is no minimum order requirement, but each order carries a $5.95 flat fee for same-day or next-day deliveries.