The concept isn't new: planes have been landed automatically based on radio waves of the ILS system. But compared to a landing procedure on a single runway in a controlled space with necessary ground equipment to aid in the process, car traffic is not so much static.
The automatic following system will bump into fundamentals and the close proximity of the participating cars will only magnify their effect.
Consider a ten car "train" (or convoy) following the first car automatically. Their speed is higher than usual and they drive within a few meters of each other, all carefully controlled by a computer. Then the first car hits a big elk (moose).
The weight of the animal itself is sufficient to cause a significant, sudden decrease in the speed of the car body. While the sensors on the second car do notice that the first car slowed down (due to the impact), it cannot possibly brake to a stop without hitting the first car. If the convoy is driving 100 km/h no car is going to stop in time if the forecar loses a significant percentage of its speed in a short flash.
Now, what happened between the first and the second car will continue to propagate far back in the convoy and the end result is a pile of ten cars mostly crushed into each other.
Maybe there are no elk on a highway. Make it someone who had learned his driving skills on a Russian highway (you must have seen the Youtube videos). Or someone's tire blows up and that car spins to the adjacent lane straight in front of the first car.
But there's a good reason to have a speed-dependent 2-4 second safety margin between cars, and robotic controls and computerised radio links aren't going to change the physics.
You don't even have to hit a sudden obstacle to get problems, trains of vehicles also add the problem of increased harmonics. Say the second car oscilates with +/-10cm from the desired length from the first car. How will this propagate to the last car if they all have the same controller, or if they all have different controllers? I know the uni here has been doing research about this exact problem in cooperation with volvo cars.
I agree with you that this may not be revolutionary, but with some relatively realistic numbers (1300 kg lead car, a giant 1500 kg moose, 80kph road speed, 6m following distance, 7m/s^2 max decel of following vehicles), it looks like you'd only have the first two or three cars collide, and probably not hard enough to cause life threatening injuries in the second car. I'd think that tuning the following distance to the road speed (and, possibly more morbidly, the mass of the lead car relative to the foreseeable obstacles, which I'm not entirely sure that Volvo wasn't tacitly doing in the test) would be adequate to come up with a safe following distance well shorter than 2 seconds, where fuel economy gains obviously kick in as well.
The practical reaction time for mid-cruise humans is pretty terrifyingly slow sometimes. Pair that with suboptimal panic behavior and I believe that there's some significant efficiency and maybe even safety gains to be made. Granted, there is a limit.
I heard about similar tests with 2 cars, one following another and they were driving around different countries - they had issues in Russia as someone would occasionally slip in between them breaking the link.
Google research is much more interesting since car is independent, but much more demanding on a road data.
The simple way to solve that is the same way human drivers are taught to solve this: by following at a safe distance. I was taught to follow at my own stopping distance, so that if the leading car were to hit a brick wall and stop immediately, I would still have time to stop myself.
The automatic following system will bump into fundamentals and the close proximity of the participating cars will only magnify their effect.
Consider a ten car "train" (or convoy) following the first car automatically. Their speed is higher than usual and they drive within a few meters of each other, all carefully controlled by a computer. Then the first car hits a big elk (moose).
The weight of the animal itself is sufficient to cause a significant, sudden decrease in the speed of the car body. While the sensors on the second car do notice that the first car slowed down (due to the impact), it cannot possibly brake to a stop without hitting the first car. If the convoy is driving 100 km/h no car is going to stop in time if the forecar loses a significant percentage of its speed in a short flash.
Now, what happened between the first and the second car will continue to propagate far back in the convoy and the end result is a pile of ten cars mostly crushed into each other.
Maybe there are no elk on a highway. Make it someone who had learned his driving skills on a Russian highway (you must have seen the Youtube videos). Or someone's tire blows up and that car spins to the adjacent lane straight in front of the first car.
But there's a good reason to have a speed-dependent 2-4 second safety margin between cars, and robotic controls and computerised radio links aren't going to change the physics.