This one happened to be right in the middle of the dirt road on the way to do the morning chores.
This could not have been laid in a nest for it was quite a distance from any structures or grassy areas where it could be hidden safely. It had not been dropped from a distance because there were no cracks in the thin shell. I can only assume some unsuspecting-expecting robin happened to be walking, along minding her own business, when she plopped out an egg and left it knowing that she had no protection to brood her possible offspring. It must have come as quite a surprise.