Actually, a lot of the imagery nowadays is aerial, even though they still call it "satellite." Much less expensive at the resolutions they have. (You can see the horses in my neighbor's pasture, 30 miles from nowhere.)

And as I said, they all update on different schedules, so I always use Bing and Yahoo as well as Google when it's important to get it right.

I forgot to mention them in my earlier post, but the gazetteers are also inaccurate as to which roads are paved.

No, you can't always tell from the imagery. But often enough to make it worthwhile to zoom in and compare the color of the road surface with the color of people's driveways and intersecting roads, etc.