The first sentence of section 494 of this title, and section 502 of this title, shall be inapplicable with respect to any bridge to which the provisions of this subchapter are applicable, except to the extent provided in this section.
Any bridge, the construction, reconstruction, or alteration of which was required by an order of the Secretary issued prior to July 1, 1939, and was not completed on such date, and in the case of which no penalties have accrued at the time of the enactment of this subchapter, shall be constructed, reconstructed, or altered as required by such order, and not in accordance with the provisions of this subchapter. In the case of any such bridge, however, the Secretary shall apportion the cost of the project between the bridge owner and the United States, and payment of the share of the United States shall be made, in the same manner as if the provisions of this subchapter applied to such construction, reconstruction, or alteration, subject to the following limitations:
(1) In case such construction, reconstruction, or alteration has not begun on or before April 1, 1940, such apportionment of cost shall be made only if (A) the construction, reconstruction, or alteration is carried out in accordance with plans and specifications, and pursuant to bids, approved by the Secretary, and (B) the bridge owner has submitted to the Secretary a written guaranty of cost as provided for in section 515 of this title.
(2) The Secretary's determination as to such apportionment, and as to such plans and specifications and bids, shall be final.
(3) Such apportionment shall not be made if such construction, reconstruction, or alteration is not completed within the time fixed in such order of the Secretary or within such additional time as the Secretary, for good cause shown, may allow.
Any bridge (except a bridge to which subsection (b) applies) the construction, reconstruction, or alteration of which was required by an order of the Secretary issued prior to July 1, 1939, and was not begun before such date, shall be subject to the provisions of this subchapter as though such order had not been issued, and compliance with the provisions of this subchapter and with such orders as may be issued thereunder shall be considered to constitute compliance with such order issued prior to July 1, 1939, and with the provisions of law under which it was issued.
(June 21, 1940, ch. 409, §12,