In this Division—
severe risk breach lower limit, for a particular mass requirement applying to a heavy vehicle, means a mass equalling 120% of the maximum mass (rounded up to the nearest 0.1t) permitted for the vehicle under that mass requirement.
substantial risk breach lower limit, for a particular mass requirement applying to a heavy vehicle, means the higher of the following—
(a) a mass equalling 105% of the maximum mass (rounded up to the nearest 0.1t) permitted for the vehicle under that mass requirement;
(b) 0.5t.