Sec. 14. "Weighted average useful life" of a project or projects means:
(1) the sum of the products of the cost of each asset comprising the project or projects and the useful life of the respective asset; divided by
(2) the total cost of all the assets comprising the project or projects.
For purposes of this computation, the useful life of land is fifty (50) years. The useful life of all other assets comprising the project shall be conclusively evidenced by a certificate of the department based on its experience in maintaining transportation systems. The weighted average useful life of any project shall be determined as of the later of the date on which the project is expected to be placed in service and the date on which the bonds or notes are issued.
As added by P.L.68-1988, SEC.12.