The local planning authority—
shall keep under review the matters which may be expected to affect the development of their area or the planning of its development; and
may, if they think fit, at any time institute a fresh survey of their area examining those matters.
Without prejudice to the generality of subsection (1), the matters to be kept under review and examined under that subsection shall include—
the principal physical and economic characteristics of the area of the authority (including the principal purposes for which land is used) and, so far as they may be expected to affect that area, of any neighbouring areas;
the size, composition and distribution of the population of that area (whether resident or otherwise);
without prejudice to paragraph (a), the communications, transport system and traffic of that area and, so far as they may be expected to affect that area, of any neighbouring areas;
any considerations not mentioned in paragraph (a), (b) or (c) which may be expected to affect any matters so mentioned;
such other matters as may be prescribed or as the Secretary of State may in any particular case direct;
any changes already projected in any of the matters mentioned in any of the previous paragraphs and the effect which those changes are likely to have on the development of that area or the planning of such development.
A survey under subsection (1)(b) may relate to only part of the area of an authority; and references in subsection (2) to the area of an authority or any neighbouring areas shall be construed accordingly.
A local planning authority shall, for the purpose of discharging their functions under this section of examining and keeping under review any matters relating to the area of another such authority, consult with that other authority about those matters.