You seem to be ignoring one alternative; no distractions whatsoever.

In what universe are vehicles sold without dash mounted radios and nav systems? Those are dramatically more distracting than a HUD, as they require the user to avert their eyes from the road for use.

I was recently shopping for a car, and I will tell you now, I did not see a single one that had a front seat with no displays or controls besides the steering wheel, pedals and speedometer.

It's true, cars have headlight switches, tachometers, gas gauges and electronic mirror controls. The horror.

The only devices that can actively command your attention are the gauges & lights in the instrument cluster (which are all important to driving safely) and possibly the screen on your radio. Speaking of which, I hated the old radio on my old car, because it was too bright and had too much activity on the display.

> It's true, cars have headlight switches, tachometers, gas gauges and electronic mirror controls. The horror.

You forgot climate control, cruise control, a confusing array of wiper settings, CD controls, radio, bluetooth, GPS, fuel efficiency feedback and probably a few others I didn't think of right off the top of my head. The point is not that cars are insanely distracting, but just that Glass is probably not the most distracting thing in your car.

Many of these have similar risk cost vs. risk reward tradeoffs. Climate control helps keep you focused (I know I have a hard time focusing on the road when it's 40F in my car) and cruise control helps keep you predictable to other drivers.

Bluetooth integration assumes people are going to use their phones either way, and thus handsfree is the safer choice. GPS informs drivers in advance so they don't have to swerve across seven lanes of traffic to make their exit.

My point is, what problem does Glass solve that makes it worth the risk?

If future iterations of Glass are able to incorporate existing dash functions, thus making them safer to access by not having to take one's eyes off the road, then the benefits are obvious.

Future iterations of Glass are still exactly that- in the future.

Doesn't Glass play music and navigate?

If so, it already incorporates some of those functions.

It isn't a true "HUD": it is a tiny screen sitting next to one eye in the extreme corner of your vision; it requires a massive refocus of your eyeballs to see the screen, and in the process your other eye totally loses its ability to focus on anything at all. If you want to look back at what you are doing, you have to move your eyes, refocus them, and even resynchronize them. The point of a "HUD" is that you can see updated information while continuing to stare straight ahead and focus on your target: Glass is not a HUD.

True, but I'm pretty sure that setting up your laptop behind the steering wheel is already illegal.

I refer to existing dash mounted radio-nav systems found in virtually every vehicle.

Google Glass isn't a radio-nav system any more than it's an Angry Birds control center.

But I think one of the main arguments is that using Google Glass for heads-up GPS navigation is safer than looking down at your dash.