Amazon this week said it plans to expand its Amazon Scout last-mile delivery robot service to customers in Southern California, moving beyond its initial testing area of the Pacific Northwest.

In a blog post, Amazon Scout vice president Sean Scott gave an update on the development of the mobile robot and some of the challenges the development has faced, including neighborhood obstacle environments, weather, and unexpected surprises.

“One of our favorite parts of this journey so far has been witnessing how excited customers are when they see the delivery device for the first time, and how they’ve welcomed Scout in to their neighborhood,” Scott said in the blog post. “In the span of a week, our Ambassadors witnessed a child ask her dad for a Scout for Christmas, and another customer ask if he could hitch his two dachshunds to Scout and use it as a dog walker. While the intent of our ‘adora-bots’ is and will remain delivery, we couldn’t help but chuckle at these reactions. We have a lot of pride packed inside these cooler-sized devices and love to see such a positive reaction from the community.”

The Southern California expansion will be for customers in the Irvine, Calif. area, with a small number of Scout devices performing deliveries Monday through Friday, during daylight hours. Amazon said customers in the Irvine area can order just as they normally would, and their Amazon packages will be delivered by either a regular carrier partner or by Amazon Scout. Delivery options via Scout include same-day, one-day or two-day shipping for Prime members. The Scout robots will autonomously follow a delivery route, and will initially be accompanied by an “Amazon Scout Ambassador,” the company said.

Delivery robots across the nation

Amazon is not the only company experimenting with last-mile delivery robots. A flurry of mobile robots are hitting the streets and sidewalks with small package delivery or larger delivery options such as groceries. In April, Starship technologies announced it had passed a milestone of making 50,000 commercial deliveries with its mobile robots. Since they began delivering groceries and items from a Co-op food store in Milton Keynes, U.K., in April 2018, Starship’s robots have now traveled more than 200,000 miles, completing thousands of deliveries per week. The company announced a new partnership with a second Co-op store in Milton Keynes as well. The company also provides mobile robot deliveries to college campuses at Northern Arizona University and George Mason University in Fairfax, Va.

Other last-mile delivery robot services over the past year include Uber Eats, which tested food delivery via aerial drone in San Diego; Postmates, which is planning package delivery via mobile robot in Los Angeles; Nuro, which plans on delivering Domino’s Pizza in Houston as well as continuing its grocery delivery service in Arizona; Boxbot, which plans self-driving parcel delivery services in California, and FedEx, which is testing food delivery with Pizza Hut.

The market for delivery robots is expected to grow at a compound annual growth rate of 19.15% over the next five years, reaching $34 million by 2024, according to a Market and Markets report. Driving the market is a cost reduction of last-mile deliveries, from $1.60 per delivery via human drivers, down to $0.06 per delivery through autonomous robots, the company said.