Maybe its age, maybe its just me, but I am finding that concentrating on driving is as much as I can do, and fiddling with sat nav or even talking on the hands off phone can be distracting. This morning, on my way to play race officer for a yacht race, I was talking to my race officer predecessor about tide, weather and the best course, and I went through some lights just as they were changing form orange to red.
This is a first for telephone ditraction but not for satnav which is why I use blue tooth and an earpiece rather than a screen when on the bike. I've seen truck drivers texting whilst their rig waves about the lane and I've had the same happen to me when using the sat nav.
As I said at the beginning , this maybe just me but I do wonder. I'm not a pious H&s type - far from it. My inclinations are always to ignore rules. But is using a satnav with a screen whilst the car is moving safe? I doubt it.
Howard this is a big topic among pilots of light aircraft. The iPad (with navigation app) is now ubiquitous and as many planes don't have the panel space it is usually strapped to the knee. This means more time with head in the cockpit and not looking out for other traffic. The amount of information these devices can provided is fantastic but it is a big distraction from flying the plane and avoiding others. This is exactly the problem you are describing and yes it will lead to accidents. We need a device to whack us around the ears or provide an electric shock three seconds after our eyes shorten their focus from outside the cockpit to inside. Morgan cockpits included.
Some will recall the helicopter crashing into a crane in central London a couple of years ago. The results were tragic and according to the investigation, texting by the pilot, "was a mechanism that could increase stress and introduce rapid changes of plan." i.e. it's likely to have been a contributing factor.
Enough sailors have done just that.