Say it wants to let a pedestrian know that it’s going to yield for them, Kashani says. “It would use its eyes; it would look down,” he explains…

And using eye movements—and other non-verbal cues—is a good strategy, says Aaron Steinfeld, an associate research professor at Carnegie Mellon University who focuses on human-robot interaction and advanced transportation systems. He likes that the rover is capable of “deferential behavior,” which he says isn’t common with robots.

Serve is intended for sidewalks, and Steinfeld says that environment is challenging. It’s easy for people to move fluidly with a crowd—they usually can do it (with varying degrees of success) while staring at a smartphone. For a bot, that’s a lot. “We actually have active research on robots navigating socially around people when they’re moving,” he says. “And it’s really tricky to do this well.”
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