Restrictions on towing of trailers
14.—(1) Except as stated in sub-paragraph (2), engineering plant must not tow a trailer.
(2) Engineering plant falling within sub-paragraph (3) may tow—
(a)a trailer which is itself engineering plant; or
(b)a living van or office hut used in connection with the construction, maintenance or repair of roads.
(3) Engineering plant falls within this sub-paragraph if it is a motor vehicle with an overall length that does not exceed 8 metres.