(1) Where it appears to the road authority charged with the maintenance of a public road that, having regard to the average expense of repairing that road, extraordinary expenses have been or will be incurred in repairing the road by reason of the damage caused by excessive weight passing along the road or other extraordinary traffic thereon, the amount of the extraordinary expenses shall be paid to the road authority by the person by whom or in consequence of whose order such weight or traffic has been conducted and, in default of that amount being so paid, it shall be recoverable as a simple contract debt in any court of competent jurisdiction.
(2) Subsection (1) of this section shall have effect subject to the following provisos:
(a) any person required by the subsection to pay extraordinary expenses may enter into an agreement with a road authority for the payment to them of a composition in respect of the relevant weight or traffic and, on paying the composition, shall not be liab
…