Ford is working with Postmates and Walmart on a pilot program for self-driving grocery deliveries, the companies announced on Wednesday.

"We are exploring how self-driving vehicles can deliver many everyday goods such as groceries, diapers, pet food and personal care items," Ford said in a press release.

The grocery delivery pilot experiment will be based in Miami, where Ford's self-driving car company, Argo, is already testing self-driving vehicles. Ford had been testing self-driving deliveries with Postmates prior to this announcement.

Like most car companies, Ford is racing to develop fully autonomous vehicle technology. But Ford has been more proactive than most of its competitors in exploring the non-technical aspects of a self-driving car service. Last year, I got to sit in the seat suit of a fake self-driving car Ford was using to test pedestrian reactions to self-driving car technology. Ford also experimented with delivering pizzas with mock-driverless vehicles in a partnership with Dominos.

Ford's collaboration with Postmates over the last few months has been focused on figuring out the best way for customers to interact with a delivery vehicle. Driverless cars won't have a driver to carry deliveries to the customer's door, so self-driving vehicles will need some kind of locker that customers can open to remove their merchandise. Ford has been experimenting with multi-locker delivery vans, allowing its cars to serve multiple customers on a single trip—without worrying about one customer swiping another's deliveries.

Ford also announced last month that Washington, DC would be the second city where Argo will be preparing to launch a commercial service in 2021 (in addition to Miami). Ford has worked hard to cultivate relationships with local government officials, with Mayor Muriel Bowser attending last month's announcement on DC's waterfront.

Ford is betting that all of these preparations will help the company scale up quickly once its self-driving technology is ready. That's important because Ford appears to be significantly behind the market leaders: Waymo (which is aiming to launch a commercial service this year) and GM's Cruise (aiming to launch in 2019). But it's also a risky strategy because if Argo's technology isn't ready on time, then all of Ford's careful planning could turn out to be wasted effort.