I really don't see the point of autonomous driving if you still have to be alert to take over if the car makes a mistake. If I'm driving I am fully alert and my reaction times are in fractions of a second. If the car is driving that reaction time is necessarily increased or multiplied by the "what the heck is the car doing" factor and the need to get hands and feet in the right position. If it hits a child for example you may be too late to make any difference and legally it's still your fault.
The car can react faster and see more than you. Can, not always. I have three distinct moments with the 2 autonomous cars I've had:
The first was me stopped at a red light, with a van in front of me. Car was a light hybrid, so the engine had shut off. We were stopped for at least 10-15 seconds and were just talking. Suddenly the engine roared to life and the car automatically, rapidly, moved into the turn lane. The car behind us wasn't stopping and ran into the van.
Second time was similar, on the highway when traffic is rapidly coming to a stop, as was I. I actually was manually driving in heavy traffic, but in this system the driver is just an input in the logic. I remember the car making two loud beeps with a large ⚠️ on the dash and the car took over. A split second later I heard tires screeching behind me and pulled my hands off the wheel and brought them to my chest and braced for impact...but there wasn't one. I did hear loud scraping outside the car. When I looked up, the car was stopped and there was a smoking pickup truck next to me. The driver was too busy playing on their phone.. my car sensed they weren't stopping, so it took over, and in the process it apparently strobes the tail lights at 150% brightness much like a police car. That got the driver's attention and he swerved, avoiding me, but he scraped the entire side of his truck on the wall. He even said that if my car hadn't strobed the lights, he would have plowed right into me at 60+ mph.
Third was a different situation. Some old fart completely blew through a stop sign and went across a 6-lane divided highway, right in front of me. I couldn't see the car because of other cars blocking it...but my car did. It slammed on the brakes and swerved away, avoiding the accident.
These systems, when well-equipped (multiple, multi-band sensors...not the single sensor Tesla tries to use), and well-tuned, are capable of preventing or at least minimizing accident impacts. They can't prevent 100% of them. Case in point: I was driving a prototype last month and a bus in front of me kicked up a 3'x3' piece of plywood way up into the air. I could see it, but the car didn't. I slammed on the brakes but still ended up whacking the front bumper of the car with it. At least it didn't go through the windshield or glass roof. We pulled the logs and the car never detected it. Likewise, these cars don't react to potholes...yet.
Anyone remember the buzz about "vehicle-to-vehicle communications?" In addition to the car's own sensors, they were supposed to be able to communicate with
each other to help avoid accidents. The FCC even set aside some radio frequencies for this. But unless I'm missing something. that idea has fallen by the wayside in favor of trusting the cars to make their own decisions autonomously. And we're seeing how well this is working out.
My car actually has this...but I've never seen it actually communicate with another car. Then again, most of the time I have an Android PC running things over the top of the factory systems. Bosch still has it available, but I don't know if any manufacturers are still using it.
Can't imagine any system being capable of taking care of such situations, no matter how rapid-reacting or "automated." About the only way to cure that sort of impediment-on-vehicle situation is to erase all impediments from such roadways. Can't really do it in residential areas. Will almost certainly be able to do it in custom-designed and -blocked-off highways, tunnels, etc. Even then, you never know. Like humans, "critters" can be inventive and quick.
They can... remember, if these systems are properly tuned, they
know the distance between you and the object/kid/critter. They know the current speed, know the current level of traction, even wind loads, and calculate what stopping distance is needed. If need be, they can swerve as well. It's much like piloting a modern Airbus -- unless there's a system malfunction (see QF32), the aircraft really does know better than you most of the time. I treat mine as a second set of eyes. Within the first hour of picking up my current car, I found myself behind a driver with NO brake lights whatsoever. They were installed but never worked. The car picked up on their car slowing down before I did.
If anything automatic braking sys in my passport is counterproductive, I have no idea if it would even sense a person, but those few times it did kick in, it put me in more danger, few times i had to swerve to avoid hitting a car in front, but the system hit the brakes and would not release them until the car almost stopped, on the highway!!! On curved roads with no divider it thinks oncoming cars, are cars in front of me traveling in the same direction, the radar sees distance rapidly shrinking and hits the brakes. several times i almost got rear-ended because of the system., Good thing I can shut off the radar brakes, but it puts them on again every time I restart the car.
The quality of the various "assist" systems varies widely, even within the same model year of the same manufacturer. One of the worst I ever saw was the last model year of the VW Passat. During multiple test drives, the automatic systems would just give up with no warning, just a beep and it was expecting you to take over immediately, sometimes putting you in bad position. Mazda's is much better and agreeable but still uses a very simplistic algorithm when controlling the brakes.
Bosch Telematics gets my vote. Some pretty neat algorithms in there. I'm a fan of the tailgater algorithm -- The car basically draws a box between you and the cars around you.. It knows how much distance you need to stop to zero with the current conditions. It then takes that distance, adds a multiplier, and assumes that's what the vehicle behind you (it differentiates between car and truck) needs to stop. If it senses that if the car in front of you comes to an abrupt stop, and you won't be able to stop without the car behind you hitting you, it will automatically start to slow down to increase the amount of distance available to stop. We've had countless hours of fun watching tailgaters trigger the algorithm and watch them "argue" with the car. They get too close and the car gradually slows down.
The Mrs. and I have adopted this into our own manual driving, and it actually saved my life one night. She was driving, I was in the passenger seat, in her car. Some asshat was riding hers despite her being in the right lane. She was getting upset about it so I told her to just take her foot off the gas. It took some convincing, but she did, and Mr. Asshat angrily passed us and got in front of us. Two lights later was a red light, and he was the first car, we were the second. Light turns green, he goes and gets T-boned with the other car driving about 50mph. Rolled him multiple times before his vehicle landed against a business sign. That would have been us if we hadn't forced the guy to go around us.