Yes, I absolutely do think that some kind of car-to-car communication is required for these situations.
It's not an impossible problem to solve, but I have not heard of any efforts to create a car-to-car or car-to-road communications protocol and infrastructure that would be cross-manufacturer and/or internationally approved.
In my opinion, before such a mechanism exists, autonomous cars will only work as long as the majority of cars are driven by humans. I will change my opinion when I see a demonstration of a city (or city-like test site) traffic where all or the majority of cars are autonomous.
There's a lot of academic work on Vehicle Adhoc Networks (VANETs) - https://en.m.wikipedia.org/wiki/Vehicular_ad_hoc_network has some sources. We discussed it a little at university in a module about mobile/sensor nerworks, it's definitely an interesting research area.
It's not an impossible problem to solve, but I have not heard of any efforts to create a car-to-car or car-to-road communications protocol and infrastructure that would be cross-manufacturer and/or internationally approved.
In my opinion, before such a mechanism exists, autonomous cars will only work as long as the majority of cars are driven by humans. I will change my opinion when I see a demonstration of a city (or city-like test site) traffic where all or the majority of cars are autonomous.