Level 1 is already common in many cars whose drivers don't even know it. This entails preventing exactly the issue discussed, protecting drivers against mistakes and sudden occurences. If a child runs out on the street, for example, the car will try to warn the driver and maybe even stop the car. In fact, only level 2 tests the driver's reaction time. Level 3 gives the drivers minutes of warning before handing off control. Level 4 can drive safely within a geographic area. The advantage of this latter level would be tremendous for seniors. If they can reliable be driven to the local community center or library without needing to ask somebody that would do wonders for their autonomy. Never mind that they can't drive anywhere on a whim, they could get out of their home and be with other people.
