The autonomous delivery startup Nuro has raised $940 million from The Softbank Vision Fund, making it one of the most lavishly funded startups in the driverless car sector. The news comes after Nuro became one of the first startups in the world to begin operating a fully driverless commercial service on public roads.

Under a deal announced last year, a Kroger-owned Fry's Foods store in the Phoenix area is using Nuro's technology to deliver groceries to nearby customers. Initially, the deliveries were conducted by modified Toyota Priuses. But in December, Nuro added two custom-designed robots to its fleet. These robots are smaller than a conventional car and are fully driverless—they don't even have space inside for a human driver to sit.

"Our goal this year is to really scale to an entire city worth of operation," CEO Dave Ferguson told Ars last week.

Nuro's robot has a top speed of 25 miles per hour (40 km/h), which simplified the jump to fully driverless operation. A vehicle moving at 25 miles per hour has a much shorter stopping distance than a vehicle traveling at 65 miles per hour. That means the vehicle doesn't need to see as far ahead, and its software doesn't need to predict other vehicles' behavior too far in advance. In the rare event that a Nuro robot does run someone or something over, its lower mass and speed means it's also much less likely to cause serious damage.

While Nuro's two custom robots are fully driverless, they are currently being followed around by human-driven vehicles with the capacity to intervene if the robots malfunction. Ferguson told Ars that he hopes to stop using the chase vehicles by next quarter.

Nuro was founded in 2016 by Ferguson and Jiajun Zhu, both veterans of Google's self-driving car project. The latest fundraising round represents a dramatic 10-fold increase over Nuro's previous funding round. A year ago, Nuro raised $92 million.