The problem is that you encounter edge cases on every drive, and you need to be ready to respond. The car may be able to handle 80% of the trip, but one of those edge cases will sneak up on you and the car. How long would it take you to regain situational awareness and safely maneuver the car in the event of some unexpected situation after you've been cruising in self-driving mode for an hour? Ten seconds? Five? Can you do it in one? What if the car doesn't realize it can't handle the situation at all?
Like any risk, you also need to consider the impact of getting it wrong. If an audio assistant gives you the wrong answer to the population of your hometown, no big deal. But if your car thinks everything is okay and drives you into a stationary fire truck on the shoulder of a freeway when you are travelling at 70mph, the downside of that edge case is infinitely worse.
Sure, humans can make these mistakes, too. But the fact is that your notional world where computers are able to make smarter decisions than humans about how to drive doesn't actually exist. No one has figured out how to make it work. And they won't anytime soon. They've solved all the easy parts. But it turns out there's a lot more involved in driving than all the billions of dollars poured into the problem so far can figure out.
- more data, (historic on how to act on certain situation, live data for event i.e. sensor data, lidar/radar data, images) vs human driver who would not have access or the ability to process these.
- faster and parallel processing vs human driver
- single focus/goal (of driving from x to y safely and making appropriate decisions to achieve it) vs human driver (with "physical limitations", "emotions", "hormones" and other things that makes up "life") is more likely to be distracted...
computer with all of above advantages compared to human driver may able to make better informed decision much faster than human driver can do (and when it doesn't it's hard to know/prove if human driver would consistently make better decision every time for same situation)
having said above, I agree that tech is in its infancy and it's gonna take a decade or two to be matured and even after that human intervention just in time in some cases would be needed but for the most controlled/learned environment (which is 70-80% of total driving on day to day basis) these systems would be immensely helpful.
Like any risk, you also need to consider the impact of getting it wrong. If an audio assistant gives you the wrong answer to the population of your hometown, no big deal. But if your car thinks everything is okay and drives you into a stationary fire truck on the shoulder of a freeway when you are travelling at 70mph, the downside of that edge case is infinitely worse.
Sure, humans can make these mistakes, too. But the fact is that your notional world where computers are able to make smarter decisions than humans about how to drive doesn't actually exist. No one has figured out how to make it work. And they won't anytime soon. They've solved all the easy parts. But it turns out there's a lot more involved in driving than all the billions of dollars poured into the problem so far can figure out.