9 Alterations to public works and changes of use.E+W
(1)This section has effect where, whether before, on or after the commencement date—
(a)the carriageway of a highway has been altered after the highway has been open to public traffic;
(b)any public works other than a highway have been reconstructed, extended or otherwise altered after they have been first used; or
(c)there has been a change of use in respect of any public works other than a highway or aerodrome.
(2)If and so far as a claim in respect of the highway or other public works relates to depreciation that would not have been caused but for the alterations or change of use, this Part of this Act shall, subject to subsection (3) below, have effect in relation to the claim as if the relevant date (instead of being the date specified in section 1(9) above) were—
(a)the date on which the highway was first open to public traffic after completion of the alterations to the carriageway;
(b)the date on which the other public works were first used after completion of the alterations; or
(c)the date of the change of use,
as the case may be.
(3)Subsection (2) above shall not by virtue of any alterations to an aerodrome apply to a claim in respect of physical factors caused by aircraft unless the alterations are runway or apron alterations.
(4)Where a claim relates to such depreciation as is mentioned in subsection (2) above the notice of claim shall specify, in addition to the matters mentioned in section 3 above, the alterations or change of use alleged to give rise to the depreciation; and if and so far as the claim relates to such depreciation—
(a)section 6 above shall have effect as if the increase in value to be taken into account were any increase that would not have been caused but for the alterations or change of use in question;
(b)subsection (1) of section 8 above shall not preclude the payment of compensation unless the previous claim was in respect of depreciation that would not have been caused but for the same alterations or change of use, and subsection (2) of that section shall not preclude the payment of compensation unless the works for which the land was acquired were works resulting from the alterations, or works used for the purpose, to which the claim relates.
(5)For the purposes of this section the carriageway of a highway is altered if, and only if—
(a)the location, width or level of the carriageway is altered (otherwise than by re-surfacing); or
(b)an additional carriageway is provided for the highway beside, above or below an existing one;
and the reference in subsection (2) above to depreciation that would not have been caused but for alterations to the carriageway of a highway is a reference to such depreciation by physical factors which are caused by the use of, and the source of which is situated on, the length of carriageway which has been altered as mentioned in paragraph (a) above or, as the case may be, the additional carriageway and the corresponding length of the existing one mentioned in paragraph (b) above.
(6)In this section “runway or apron alterations” means—
(a)the construction of a new runway, the major re-alignment of an existing runway or the extension or strengthening of an existing runway; or
(b)a substantial addition to, or alteration of, a taxiway or apron, being an addition or alteration whose purpose or main purpose is the provision of facilities for a greater number of aircraft.
(7)For the avoidance of doubt it is hereby declared that references in this section to a change of use do not include references to the intensification of an existing use.