Duplicate Streets

while editing today in this area: http://www.openstreetmap.org/?lat=53.77795&lon=-1.77487&zoom=17&layers=B000FTF i noticed that there are an awful lot of duplicated streets/roads… is there a reason for this? it seems to be in areas that are very well covered by OSM but i noticed some are correctly joined to other streets while some aren;t - surely this would cause weird routing once it is used?

MaFt

It looks like this changeset created loads of duplicate ways: http://www.openstreetmap.org/browse/changeset/1420551
And this previous changeset duplicated loads of nodes: http://www.openstreetmap.org/browse/changeset/1420511

I’m not sure why. It looks like they were using some sort of bulk upload script, and it uploaded ways that were already there.
Probably best to contact that user and check what they were doing, and if they were aware of the duplicates. Maybe those changesets should be reverted.