The policy is somewhat interesting as there are more odd days than even (if a month has 29 or 31 days then there will be two odd days in a row at the end of the month) yet it also allows more plates on the odd days (odd numbers + all other characters). If the last character on the NY plates is evenly distributed then there will be disproportionally more vehicles filling up on the odd days and it would be better to drive an even-numbered vehicle.