"main road"

means a public road which is a main road in terms of any law in force in the province in which the road in question is situate, or any public road which has been constructed or has at any time been maintained by or under the authority of an Administrator by means of funds at his disposal, and from which he has not withdrawn his control: Provided that any public road on which any labour has been expended shall, for the purposes of this Act, be deemed to be a main road, unless it is proved not to be a main road;

[Definition substituted by section 29 (Schedule) of Act No. 54 of 1971]