[Faark]

Cooperative strategies open up a lot of new attack vectors. I don't trust those companies to design systems robust enough, especially if they'd have to build a standard together with competitors.

And in the end, your car has to be able to come to a safe stop and avoid dangers no matter the situation. Even with no other cars around or communication interrupted. To reliably achieve this will probably get you most of the way to "real" self driving, with humans/remote operators manually taking care of the few remaining cases.