> Level 4 doesn't require driver attention, it just requires the driver to be (instantly?) available if the system has a problem Based on my best understanding

> Level 4 doesn't require driver attention, it just requires the driver to be (instantly?) available if the system has a problem Based on my best understanding of the article and the good description on these levels in the CES keynote linked in the article... This is Level 2, when the driver must be available instantly. Level 3 is when there driver must be available but there's plenty of time (the article mentioned 15 seconds) to swap. Level 4 should not need any human intervention when engaged. It can only be engaged when it's safe to do (e.g. in a city in good weather conditions) but once it's enabled, it fulfills the task given to it without ever needing to fall back to human hands. You should be able to sit on the back seat drinking beer. Level 4 should be able to safely stop the car and wait for assistance if things go bad without driver intervention. Level 2 is where the cars out there are now. Level 5 is a long way away.