When I discovered gasoline station road maps, I don't know. Perhaps it was the blue-on-white map of San Francisco that was always in the Hudson. Eventually, each stop for gas had me pestering the attendant for a map. These being the days, of course, when such things as gas station attendants and free road maps had not yet become the things of which legends are made. A gas station attendant was the person Father always said, "ten ethyl" to, then nodded sagely when shown the dip stick.