Your first experience with a self-driving vehicle may not be a robot taxi after all.

On Tuesday morning, a bright orange, autonomous van delivered bags of groceries from Draeger’s Market in San Mateo to two customers living nearby.

The customers met the vehicle at the curb and retrieved their bags from cubicles that line the van’s back half, opening the cubicle doors with a few taps on their phones. The doors balked a bit, taking about a minute to open, but eventually they worked.

The van’s creator, Udelv of Burlingame, is among a growing number of startups using self-driving vehicles to automate deliveries. Earlier Tuesday, a different company — Nuro of Mountain View — unveiled photos of its small delivery vehicle, which looks like a rounded silver box with a handle on top, and announced that it had raised $92 million in venture backing.

The increasingly crowded field of competitors also includes those making even smaller robots, like Starship Technologies, which started testing on San Francisco sidewalks in 2016, and Marble, which has delivered dinners for Yelp’s Eat24 service. These are slow enough, and tiny enough, to travel on a sidewalk.

So-called “last-mile” deliveries, taking place within a city or town, are more expensive than shipping goods en masse cross country. For delivery vehicles, the human driver — who must park, knock on the door and log the delivery — is one of the biggest costs.

Vehicles such as Udelv’s don’t have to protect human passengers. If something goes wrong, Udelv has programmed its vans to protect pedestrians on the sidewalk rather than its cargo.

“The worst that can happen is the eggs break and the wine spills,” said Daniel Laury, the company’s chief executive officer. “It is safer to carry cargo than to carry people.”

The company, which has not released financing details, plans to start regular deliveries from Draeger’s in February, deploying three vehicles for the task. Since they operate on public streets, all will have a technician behind the steering wheel, ready to take control in an emergency, as is required by California law. Tuesday’s test run featured two humans inside, although, according to the company, the vehicle drove itself.

Udelv’s vans will also be remotely monitored by an engineer able to take command of the vehicle — and its 18 cubicle doors — if needed. Eventually, it expects that a single engineer will monitor 10 to 15 vans at a time. Laury said the company wants to have 1,500 of its vehicles on the road by 2021.

The van is a customized Polaris GEM electric vehicle whose battery pack has been augmented to drive 60 miles on a charge. Eight cameras and six Velodyne lidar sensors — the laser version of radar — ring the top.

So far, deliveries account for just a small percentage of Draeger’s sales, said Richard Draeger, part of the third generation of his family to run the business. The store’s clientele still largely prefers to shop in person.

“They are the pickiest of the picky — they want to select their own produce and meat,” he said. “But there are staples they may want delivered at the home.”

He sees the potential for Udelv’s technology to cut delivery costs in half and shorten delivery windows. Draeger’s currently charges $9.99 for home delivery, roughly the same amount it costs the company.

Robots cannot yet handle all of the tasks that human delivery drivers perform.

“You need to find parking, then you need to make sure someone’s there,” said Sven Beiker, managing director of the Silicon Valley Mobility consulting firm and the former director of Stanford University’s Center for Automotive Research. “There may be a mean dog outside, or the recipient may say, ‘That’s not what I ordered.’”

So how will automated delivery services handle those tasks?

“If you ask all these (artificial intelligence) researchers, they’ll probably say (artificial intelligence) will figure it out,” Beiker said. “If you ask me, I’d say, ‘Don’t know.’”

David R. Baker is a San Francisco Chronicle staff writer. Email: dbaker@sfchronicle.com Twitter: @DavidBakerSF