Latest Rolls-Royce Wraith does exactly that - it uses the GPS map data to change gears in advance as it is approaching a turn in the road. I am sure that this technology will be available in ordinary cars soon enough.
Manuals have better fuel usage then automatics is a myth for recent cars, no fancy self driving needed.
Now in a high-end car with a sequential gearbox this is different, but for a small town car when you'll be doing a lot of starts and stops you'll see the losses on the hydraulic coupling.
To preempt the "but you have to own a porsche for that!" responses, I'm not saying this is cheap, I'm just saying it is not limited by the available technology, just cost.
Waze-style technology + GIS + networking with other vehicles + weather data (if you look, there is already tons of small weather monitoring stations all over major). thoroughfares).
I mean many vehicles within the last handful of years have automatic traction control that can react faster to a real time change in road conditions than any human could ever hope too. A lot of the stuff I mentioned above is just extending that foresight out further so as to not be so jarring.
My go to example is the insanity of junction 15 of the m8, that loop onto the west bound motorway is a 270 degree corkscrew rising 30 feet with a diameter of 55 yards onto a 5 lane motorway where I need to go from the left hand lane to the right hand lane (as there are entrance and exit lanes on both the inside and outside of the motorway at that point). A current automatic engine wouldn't know what was the right thing to do in that situation ( https://www.google.co.uk/maps/@55.8672951,-4.2358853,374m/da... )
To determine all of that you'd basically be at the level of self-driving car. Which would be awesome.