Length: police notification and attendants
12.—(1) Where either of the length limits set out in paragraph (2) or (3) is exceeded in relation to a Part 2 vehicle or Part 2 vehicle-combination, the user of the vehicle or vehicle-combination must—
(a)before the start of any journey, notify in accordance with Schedule 5 the chief officer of police for each area in which the vehicle or vehicle-combination is to be used;
(b)ensure that the vehicle or vehicle-combination is used in accordance with the requirements of that Schedule; and
(c)ensure that the vehicle or vehicle-combination is accompanied during the journey by one or more attendants employed in accordance with Schedule 6.
(2) The first length limit is exceeded where the overall length of any single rigid unit together with the length of any forward or rearward projection of any load carried on the unit exceeds 18.75 metres.
(3) The second length limit is exceeded where the overall length of a Part 2 vehicle-combination exceeds 25.9 metres.
(4) The reference to a single rigid unit is a reference to—
(a)a single vehicle, whether or not included in a Part 2 vehicle-combination; or
(b)any two or more vehicles comprising or included in a Part 2 vehicle-combination which together bear the weight of one or more loads in such a way that, at all times when the vehicles are moving, the longitudinal axis of each vehicle lies in the same vertical plane.