For automation to stand any chance of working, you would have to rip up the entire road network and start again. Everything would have to be totally standardised and consistent throught the land in every respect. Road layouts, lane widths, gradients, signage, stopping and parking control, avoiding overhanging objects like buildings and trees. All loose debris would have to be eliminated, drainage would have to prevent little rivers of rainfall run-off cascading across rural lanes in hilly areas. Cars would need to be able to identify areas likely to contain black ice. Who mounts the grassy bank and scrapes their bodywork on the bushes when faced by an oncoming car with a farmer in a tractor with a big trailer immediately behind it.? What if the only available passing place is on the "wrong" side of the road? Does the automated car just stop and refuse to move? Many a time I've squeezed into a gap on my right facing the traffic flow to allow an oncoming large vehicle to pass me with a clear lane. Technically I'm driving on the wrong side of the road and so is the HGV who wants to pass me, but sometimes doing that is the only way you can pass because the HGV can't get into the gap on his side whereas I can. In the real word these sorts of situations occur all the time which often require various rules of the road to be bent or broken to facilitate progress. Any half decent human driver can deal with these situations by making the best of the limited options available. If you employ rules-based automation that doesn't allow a self-driving car to do anything that is technically illegal, then you've got a recipe for chaos and gridlock.