I assume Glass is much more intrusive in for FoV. GPS are also generally optimized to be used while driving (special contrast for night use to avoid blinding the driver etc...).
And mainly, you can't use your GPS for distracting activities like watching videos, browsing the web, talking to your friends... Unless your GPS is your smartphone or tablet, in which case it's the same problem.
So, you cannot use gps for distractions, unless you can?
As for FoV - as far as I remember, the screen on Glass is quite small. The location is different from what law allows (top right instead of bottom), but still...
That article is specifically about using your phone as a GPS while it's in your hand. Using it hands-free in a car dock is a different matter (and much closer to the Glass scenario). From the article you linked:
Had Spriggs’s cell phone been fastened on a dash dock, the
story might have turned out differently; that’s because,
even though California has a hand-held ban for texting,
talking, listening (and now, using GPS), it doesn’t
prohibit hands-free cell phone use.
And mainly, you can't use your GPS for distracting activities like watching videos, browsing the web, talking to your friends... Unless your GPS is your smartphone or tablet, in which case it's the same problem.