Where a highway maintainable at the public expense is intersected, joined or continued by a highway for which the highway authority are an authority other than the highway authority for the first-mentioned highway, the following provisions have effect.

The highway authority for the first mentioned highway (“the first authority”) and the other authority (“the second authority”) may enter into an agreement as to the exercise by the second authority of that authority’s powers under sections 82 and 83 above in relation to the highway for which they are the highway authority; and any such agreement may provide for the first authority to defray the whole or any part of the expenses incurred by the second authority in consequence of the agreement.

The second authority shall not unreasonably refuse to enter into an agreement under this section; and if any question arises as to the terms (including terms as to payments) to be included in such an agreement, or whether the refusal of that authority to enter into such an agreement is unreasonable, the question shall be determined by arbitration.