Delivery robots: a revolutionary step or sidewalk-clogging nightmare?

Sharing a sidewalk with one of DoorDash's delivery robots is a bit like getting stuck behind someone playing Pokémon Go on his smartphone. The robot moves a little bit slower than you want to; every few meters it pauses, jerking to the left or right, perhaps turning around, then turning again before continuing on its way. These are the sidewalks of the future, technology evangelists promise. Autonomous delivery robots, once the exclusive purview of 1980s sci-fi movies, are coming to a city near you, with promises of reduced labor costs, increased efficiency, and the reduction of cars. But as robot fleets proliferate – Starship robots perform food deliveries for DoorDash and Postmates in Redwood City, California, and Washington DC, while Marble robots will begin making deliveries for Yelp Eat24 in San Francisco on Wednesday – the question none of these companies seems to want to answer is this: are these the sidewalks that we actually want?