While a nice piece of trivia, it's also an interesting example of how events in one area (email outage) can result in significant changes in crowd behaviour in another, and, assuming some of these accidents might have been fatal, quite literally how these influences can be a matter of life and death. What comes to my mind is the potential this shows for manipulating individual behaviour, for large scale effects, and the ethical questions that then arise.
Consider for example if a national government enforced a mobile phone data outage on a particularly dangerous stretch of road, or at particularly dangerous times. If this could be shown (as in Abu Dhabi) to save lives, would it be justifiable? Our instinctive personal reaction would probably be indignation at such restrictions, but could anyone honestly claim their email access tops the benefit of one less widow, or one less orphaned child? We already (largely) accept speed limits as a necessary curb on our personal freedom, so what would be the real difference? And of course, we're not legally allowed use a mobile phone when driving anyway, so technically only passengers could complain (any gut rejection we have I think is just another example of how immune we are to the tangible benefits to a society that can come from reducing what are to the individual, intangible risks; small changes in a massive driving population can save some lives, but we very rarely view it that way; but this is a topic for another dicussion!).
And of course, then there's Google. Given the location information it already has available, it surely is possible for Google to also detect if someone is in a speeding car, or, from knowledge of other users in the area, if they are in a group of speeding cars. Indeed, if they are using google maps navigation, then Google probably even knows which cars are going the same place. In principle, the company could delay (at least Gmail) emails being delivered, if even for a few minutes, if it detected the person was in an at risk situation. Not that there is much likelihood of them ever wanting (and hence) trying to do this, since while there might be long term commercial benefit in keeping customers alive, unfortunately no one thanks you for saving their life if they don't know it. But maybe they could use this traffic analysis in other areas - though we might get suspicious if after an accident (and our car is detected to stop suddenly in the middle of an intersection) we get a pop-up ad for the nearest breakdown service/taxi company. But the potential is there, and the likes of Google have a habit of following potential.
The point is, mobile phones represent a somewhat unique phenomenon : a system which majorly influences individual behaviour, but yet can be centrally controlled. There has been a lot of talk about 'nudge' policies, whereby society is gently prodded in a favourable direction; what the Abu Dhabi traffic incident shows is how easy this sometimes can be done directly, and to everybody. Though in this case it's more a question of what the phone didn't do.
