Originally Posted by Walter S

I don't think it will go quite like that myself. With the internet you have a gateway server at a specific IP address that forwards your message to its destination. But with driverless cars intercommunicating you have a network where the participants keep changing and the communication is with other cars in your immediate area rather than a specific gateway at a remote location. Internet-style routing just won't work because your car won't know the address of local vehicles and it would be too slow to communicate with them individually anyway. So I think it will be more of a situation where each car broadcasts information about its position/direction/speed continually. Other cars in the area receive these broadcast messages and are thus informed.

It's not a simple matter to avoid having broadcasts that stomp on each other. But there's actually already a IEEE standard for this that will probably apply well to driverless cars (802.11p). But here too, you have security concerns with people trying to hack the car network. The timing requirements for exchange of data at high speed as cars zoom around coming into and out of range don't facilitate traditional authentication techniques. So there may be all kinds of neat traffic control/optimization techniques that we'll simply shy away from for fear of hacking.

An intrusion detection system against malicious attacks on the communication network of driverless cars - IEEE Conference Publication