Just yesterday, there was a 130 vehicle crash here in the UK (sadly, that number was not a typo) after thick, low fog moved in over a bridge that is normally a major high-speed route. If everyone's vehicle had been fitted with technology that detected reduced traction due to the greasy road surface, how close vehicles in front really were and how abruptly they were slowing down even if fog was obscuring them, and how fast each driver's own vehicle was really going, and if a HUD had then flashed up the essential information and highlighted the insufficient stopping distances drivers were leaving, there might have been many fewer injuries, much less damage, and much less disruption treating the injured and recovering disabled vehicles. While yesterday's weather conditions were unusually severe for the UK, similar arguments would apply all the time at night for anyone driving on high speed or bendy out-of-town roads.
On the other hand, was I the only person who watched that video and got completely distracted by the zooming route map towards the end? If I were driving for real, I think it would be very difficult to concentrate properly on the road ahead with all of that activity going on. Avoiding information overload and maintaining driver concentration seem like serious concerns for this kind of system, but as a UI guy it looks like an awesome project to work on.