occasionally during whiteout snowstorms I glance at my GPS more as moral support that I am indeed on a road
In which case you need to be aware that GPS is generally only accurate to within tens of meters (sometimes worse), and your satnav will pin you to to the road it thinks you should be on, even if your computed position disagrees (as you will have noticed if you've ever taken a different route to that which your satnav is recommending).
In which case you need to be aware that GPS is generally only accurate to within tens of meters (sometimes worse), and your satnav will pin you to to the road it thinks you should be on, even if your computed position disagrees (as you will have noticed if you've ever taken a different route to that which your satnav is recommending).