highway=motorway does NOT indicate a road's role in the network. Rather, it's applied based on physical characteristics. All of these roads (plus Rancho Drive between Rainbow Blvd and Ann Rd, for some reason, according to Wikipedia) are controlled-access highways: There are no at-grade intersections or pedestrian crossings (except at the very end), and the speed limit is high (~60 mph), so all of these would be tagged as highway=motorway.