From New Scientist: Look, no hands: Cars that drive better than you
Ekmark says we are now entering an era in which vehicles will also gather real-time information about the weather and highway hazards, using this to improve fuel efficiency and make life less stressful for the driver and safer for all road users. "Our long-term goal is the collision-free traffic system," says Ekmark.
Ultimately, that means bypassing the fallible humans behind the wheel - by building cars that drive themselves. Alan Taub, vice-president for R&D at General Motors, expects to see semi-autonomous vehicles on the highway by 2015. They will need a driver to handle busy city streets or negotiate complex junctions, but once on the highway they will be able to steer, accelerate and avoid collisions unaided. A few years on, he predicts, drivers will be able to take their hands off the wheel completely: "I see the potential for launching fully autonomous vehicles by 2020."
This is a nice summary of the state of affairs in driverless cars. Deployment in 2020 seems likely, but the way it is with these things it seems it will be forever-off (it is 10 years in the future and always will be, like useful fusion, or peace in the Middle East) until it happens, and then it happens really quickly (if it is useful) (i.e. we will almost turn over the fleet within 10 years (perhaps 5) if this proves useful, with a few antiques (human-driven vehicles) allowed out on Sundays). I am convinced that autonomous vehicles will be perceived as quite useful by travelers, etc. (everyone except the anti-mobility crowd who will now have to explain why diesel powered driverless commuter trains enabling exurban development are good, but driverless electric powered cars enabling exurban development are bad).
Convoys, like the EU SARTRE plan, seem much more doubtful since they require far more coordination than autonomous driverless vehicles, for very little gain (slightly faster times on freeways for other people, slightly more freeway capacity) that does little for most trips (which are mostly non-freeway).