6The purposes referred to in paragraph 2 above are the following, that is to say:—
(a)the making good to the general rate fund of any amount charged to that fund under paragraph 2 above in the four years immediately preceding the financial year in question;
(b)meeting costs incurred, whether by the borough council or by some other person, in the provision or operation of, or of facilities for, public passenger transport services; and
(c)the purposes of a project connected with the carrying out by the appropriate highway authority (whether or not the borough council) of any operation which, within the meaning of the [1980 c. 66] Highways Act 1980, constitutes the improvement of a highway in the borough council’s area.