"If and when cars become driverless,..."
I think the first word is the most pertinent as far as this question goes. But there's far more to it than insurance liabilities. There's the question of just what "driverless" really means. I don't think Parliament has yet decided the interpretation. I think there are many issues to consider with Road Traffic legislation. If the vehicle contravenes any road traffic laws (e.g. by speeding, ignoring traffic signals, etc. is nobody to blame?) Furthermore, supposing the car is directed to stop by a police officer (and it presumably will not recognise that it has to do so) who is responsible for that? I cannot see Parliament allowing driverless vehicles on the road where nobody is responsible for its safe operation or where they (the occupant) is not expected to remain fit and alert. Can the occupant be drunk? Can he be asleep? Can he read the paper or watch the telly? I think "driverless" is going to have to be very tightly defined and the role and responsibility of the occupant clearly defined.