all supposition. and decades away before we're not a mixed up hash of auto & driven vehicles. If they are automatic and communicate car to car, theres no guarantee they'd need/use external indcators as they become more prevalant. hopefully by then they'll have got infrastructure sorted to keep us all apart -foot traffic too..
A lot depends on the legislative framework, and how issues of liability are handled.
One option is certainly to segregate automated vehicles from everything else - given this is the UK, it's as likely to happen by banning non motor traffic as it is from providing different thoroughfares though.
I also worry about the assumptions made in coding these things' decision trees &c, given how motor centric[1] our culture is. Look at the average cycle "facility" here to see how well intentioned people without a bicycle frame of reference can design things that vary from useless to outright dangerous. I think they are coming though - the shareholder value inherent in eliminating flesh and blood form the majority of, say, a delivery workforce will be too enticing for politicians - automated private cars will arrive as a sort of side effect.
[1] Hilariously, I've seen one of the touted advantages for automated cars being that the writer of the piece I was reading could set up an exercise bike in the back of his, and get some cardio in on the way to work. When all you can think is cars, I guess everything looks like driving. Another pearler was the elimination of parking spaces/charges, as these geniuses would have the cars circle constantly until needed for the journey home. Good job fuel is decreasing in price all the time, I guess.
