Lump sum agreement.

Notwithstanding anything contained elsewhere in this Act, the State Government or any officer authorized by it in this behalf, may agree to accept a lump sum in lieu of the amount of toll that may be payable, for such period, as may be agreed upon, by the operator to the State Government: Provided that any change in the rate of toll which may come into force after the date of such agreement shall have the effect of making a proportionate change in the lump sum agreed upon in relation to the part of the period of agreement during which such changed rate remains in force.