I can't help but imagine what happens if the computer freezes or locks up. I'd think it could end up like what happened at the end of this scene in the movie.
There would have to be hard override systems that would NEVER be prevented from being used to take over the operation of the vehicles. Drive by wire, on a system that is autonomous would be a recipe for failure and put too many lives at risk. It's no secret that properly engineered and redundant automated systems can actually prevent accidents, or at a minimum reduce the risk of injury and death in such unavoidable accidents. We have these systems in cars (and trucks), of today, and many systems have been on production vehicles for now decades. Such systems include (but are not limited to), Automatically Deploying Airbags, Seatbelt Pre-tensioners, Anti-lock brakes, Autonomous or Speed-adaptive Cruise Control, Crash-prevention; Back-up or Parking Warning (sonar sensors and alerts), Automatic Braking, Rear Cameras, Blind Side Warning, Traction Control or Skid-prevention, Active Suspension, Full-Time All-Wheel Drive, Black Ice Warning, Anti-Roll and the list goes on and on...
It's also been proven in real-world tests that have been going on for quite a number of years now, that these autonomous cars are actually far better at maintaining a vehicle on a safe path while traveling the roads than do humans, under the overwhelmingly greater percentage of road hours. That said, they are not infallible and there have been accidents. Still, I would "feel" safer in an autonomous vehicle in most cases, than I would in a Taxi driven by the likes of those behind the wheels in some I've been (un)fortunate to experience.
There are no doubt, certain very unique and fluid situations where the intuition of the human mind will make a better, safer decision than will a computer, simply because a computer as of yet, can't learn the way a human mind can. For this reason, more than any I would not (yet, and perhaps not in my lifetime), want cars, trucks, buses, or other vehicles which do not run on a fixed track to be able to be completely autonomous and be commissioned without a human in the so-called "driver's seat", while operating on the same roads with other autonomous or actively driven vehicles. I believe there needs to be a huge build-out of supporting infrastructure (limited access roadway, fully interactive traffic signalling, mesh network geographic inter-vehicle communication and navigation systems, etc.), before we're ready for this.
