Last year, a driver in the US was pulled up by a traffic cop for driving a car while wearing Google Glass.
Recently, that case was dismissed by the court. While most people are hailing the dismissal as a victory for Google Glass, one needs to read the judgement before counting the chicken.
The case was dismissed on the simple grounds that there was no evidence that the device was active while the driver was driving her vehicle. A technicality, though a valid one.
If the device had been active, the case would have taken a different turn.
Personally, I believe that using a device like Google Glass while driving an automobile is not a good idea. While people might want to compare this use with a HUD used by fighter pilots, for them the situation is quite different. For one, in most cases, they are way up in the sky. And as far as I know, the HUD information is displayed inside the cockpit, rather than on the helmet visor.