It was paid in quarters, but depending on location it was more than one quarter, this was in the days before Smart Carte cards, and all that. Also you do realize from your penultimate post that Smart Carte is ONLY in the US (I am sure someone is going to cite some second place where they have operations) and there are a lot more countries out there than the US,,,,,,,,,,,,,,,,,,,,,Quite a few European airports have the coin deposit system, and yes it is somewhat inconvenient if you do not have coins on you and there is no ready change source.