Even if every car is required to be part of the network, there may be badly maintained cars that don’t work properly, or even malicious cars, that send wrong data on purpose.
The most basic example of how this could be helpful is if the car ahead of you turns a sharp corner and crashes into a truck stopped in the road. Without car-to-car networking, you won't brake until the crash is in your line of sight.
Have you ever seen those youtube videos of massive car pile ups on highways caused by a crash, and then a cascade of additional crashes afterwards? E.g. icy conditions or dense fog. What if the original crash could communicate to cars behind it, wouldn't that be helpful if the crash isn't yet in the driver's (or car's) line of sight?
I agree "not much would change" overnight. It's just another input for the car's software to have at its disposal.
With the current hardware on the roads, I don't think it's technically possible for autos to achieve legitimate self-driving (if that's even the goal anymore?) - there are way too many edge cases that are way too difficult to solve for with just software.
We already know for sure that we can’t solve (1), which means we have to solve (2). Therefore, car-to-car communication is, at best, a value add, not the enabling technology.
You can't rely on this in real time because urban canyons make it hard to get consistent cell signal (for one thing), but you can definitely improve your models on this data once the data's been uploaded to your offline systems, and some SDC companies do this.
At this point it's all about edge cases. Certain edge cases are impossible to overcome with just software + cameras alone.
It involves a situation with networked self driving cars.
Taking things to the extreme, perhaps it’s actually a networking problem.
Cars should have the ability to send signals and hear signals from the cars around it.
Imagine if Car A could improve its own understanding of the environment using inputs/sensor data from nearby Car B.