‘‘national road‘‘

means

(a)any road or route declared a national road under section 40(1); and
(b)includes any road or route which, in terms of section 40(5), is regarded and treated as a national road so declared; and
(c)includes any part of the road which is a toll road as defined in this section, as well as any ‘‘interprovincial bridge’’ and ‘‘interstate bridge’’ as so defined which is used in conjunction with a national road;