The Atlantic writes that Carcraft began as a way for Waymo to recreate scenarios the autonomous cars experienced on the road. Some 25,000 virtual cars currently tool around "fully modeled" recreations of Austin, home base Mountain View and Phoenix, driving around 2.5 billion miles per day in 2016. Physical test vehicles logged about 3 million miles in the same time period.

"In that virtual space, they can unhitch from the limits of real life and create thousands of variations of any single scenario, and then run a digital car through all of them," The Atlantic writes.

So, in effect, it's a lot like simulation testing manufacturers use to determine a material's strength, or, say, how many times you can open a door before the hinges wear out. Carcraft could be the key to Waymo's self-driving efforts getting on the road faster.

There's an awful lot more to The Atlantic's story -- including a trip to one of Waymos' real-world autonomous testing "neighborhoods" -- so be sure to check out the links below.