Nissan is one step closer to bringing its semi-autonomous ProPilot Assist feature to American roads. The automaker has shed more light on the US-optimized version of the assistant ahead of its launch in the new Leaf near the end of 2017. As Nissan stresses, the initial version is intended only to make life easier during single-lane highway driving. Think of it as a sort of Autopilot lite. It'll use a camera, radar and sensors to keep you in your lane, maintain speed and brake if the driver ahead slows down, but it won't change lanes, handle city streets or brake in an emergency. It's definitely not a hands-free option -- it'll deactivate if you have a less-than-firm grip on the steering wheel.