Another distinction from other semi-autonomous systems is that the cars will collect data about their use, to refine and enhance the systems. That’s critical, because the real challenge for autonomous vehicles won’t be in the basics—cruising down the road and changing lanes on their own—but in the margins, the moments where the systems are challenged or stymied. This can occur with unclear lane markings, inclement weather, or dicey lane changes. What happens, for instance, if your lane is sitting still but the cars next to you are racing by and you want to shoot over? Will the car engage Ludicrous Mode acceleration to rocket you into the next lane, or sit there forever waiting for a gaping hole? Driving is all about managing those treacherous, millisecond-long transitions, which we humanoids tend to do automatically—including appropriately second-guessing ourselves midway through a move, or reacting to other drivers who are similarly tentative, or overzealous.