A few days ago I posted a bit of a rant about how excited tech reporters got over a Google press release about the company's driverless car. The problem was that, based on the details available in the reports, there didn't seem to be any significant indications of increased functionality.
Of course, reporters have a strong incentive to see signs of progress -- "just around the corner" sells better than "don't get your hopes up" -- but I think this eagerness has more than one cause (most things do) and I wonder if one of those factors might have something to do with the near-miss effect as described in this memorable story from This American Life:
Just as casinos are very good at eliciting the reactions associated with winning even when very little winning is going on, companies like Apple and Google have become very good at eliciting the reactions associated with technological progress even when the technology is advancing little and sometimes not at all. In this case, Google assumed correctly that, by showing journalists a prototype that looked different but apparently did nothing new, the reporters would react as if they had seen an advance in the technology. They respond to these meaningless press conferences in much the same way as a pathological gambler responds to two cherries out of three.
If anything, the shift to custom-made, low-speed cars would seem to be a sign of trouble. Google's stated goal is to release this technology to manufacturers in 2018. Whenever you're designing complex systems that have to work with complex systems designed by others, compatibility is usually more than half the battle. I would therefore expect some of the most daunting engineering challenges to come from getting Google's technology to work smoothly with a wide range of makes and models. The decision to go from road testing Toyota Priuses ('Prii' believe it or not) and Audi TTs to track testing what are basically go-carts does not make the four year goal look more likely.
What happens if that deadline isn't met? I suspect it will still be business as usual. Google has proven that merely symbolic progress or, failing even that, just bringing the subject up is enough to create the desired effect of public perception. My guess is that the only real deadline is beating GM, Mercedes-Benz, or Nissan or any of the other companies that have equally gifted engineers working on these problems (but with less gifted PR departments to promote them).