The key distinction here is that a Level 4 is safe even when the driver does not intervene. If it starts snowing, the car will park by the side of the road if t

The key distinction here is that a Level 4 is safe even when the driver does not intervene. If it starts snowing, the car will park by the side of the road if the driver isn't there to pick up the wheel. Level 3 is when you have ample time before the switchover, and Level 2 is when the driver must be there in a matter of seconds.