If, since July 26, 1944, and at the time of acquisition by a parish under this Sub-part, any bridge has been and is assessed with any ad valorem taxes by any parish or other political subdivision of this state or by any adjoining state in which one of the termini of the bridge is located, the parish acquiring it may provide in its resolution, mortgage, or trust indenture a contract with the purchasers of the bridge revenue bonds whereby a sum equal to what the taxes to the parish, municipality, or state, as the case may be, could be in any year following the acquisition of the bridge shall be annually paid into the treasury of the parish, municipality, or state.  This amount shall be computed by using the assessment value of the bridge in the parish, subdivision, or state as of July 26, 1944, and the rate of taxation currently being levied in the particular year.  The fund accumulated by these payments shall be used for the same purposes and in the same proportions as the taxes would have been.