In the not-too-distant future, Americans will be sharing the road with self-driving cars. Companies are pouring billions of dollars into developing self-driving vehicles. Waymo, formerly the Google self-driving-car project, says that its self-driving cars have already driven millions of miles on the open road.

In the not-too-distant past, beer has already been delivered by a robot truck in Colorado, so this shouldn't seem so far fetched.

Stanford University assistant professor Dorsa Sadigh has ridden in self-driving cars. "These cars are OK driving in normal driving conditions on normal roads," Sadigh says. But "the moment you put them in situations they haven't seen, they don't really know how to deal with that."

Swerving, braking, lane-sliding humans can make driving in the real world highly unpredictable. So someone has to teach these robots how to deal with people. That's essentially Sadigh's job: She is a computer scientist and engineer who studies the relationship between artificial intelligence systems, like self-driving cars, and humans.

Watch the video above to learn more about how The Center for Automotive Research at Stanford is studying human driving performance.

More Maddie About Science can be found at NPR.org.