United States currency shall be the basis for the published tariff. At such time as either the United States or Canadian dollar reaches an exchange rate in excess of $.05+-, then Canadian currency used in making toll payment shall be either discounted or granted a premium based on the bank exchange rate for this period. In applying the discount or premium, the official rate shall be rounded up to the nearest five percent and then applied to the base toll rates.
N.Y. Comp. Codes R. & Regs. Tit. 21 § 5704.3