Acting like a human should also help autonomous cars blend in. “You want autonomous cars to not behave robotically, in a mechanical way that is different from the way that other human drivers would react,” says John Dolan, who studies autonomous technology at Carnegie Mellon’s Robotics Institute. Google has seen the truth in this, programming its car to edge forward at four-way stops as a human would, to signal that it wants to proceed. Google’s cars also go with the flow on the highway—even if that means speeding—because its engineers believe matching the speed of traffic trumps following the letter of the law. In other words, to work within a world of human drivers, self-driving cars have to go just a bit native.