Self-intersections can be seen here:- https://tools.geofabrik.de/osmi/?view=geometry&lon=-5.27545&lat=50.21307&zoom=17&baselayer=Geofabrik%20Standard&overlays=self_intersection_ways%2Cself_intersection_points%2Csingle_node_in_way%2Cduplicate_node_in_way