 A super-4 expressway is a multi-lane divided highway with at-grade intersections, although the highway will become a full controlled-access freeway if the intersections are replaced with interchanges.A super-4 may have been a super-2 that has been twinned, although such instances of super-4 intermediaries are rare as super-2s are often upgraded right away to full freeways.Highway 40 in Ontario is a super-4 expressway between Highway 402 and Wellington St., and from Indian Rd to Rokeby Line.