In the case of the airport apron, a cleaner option is to use a [multypolygon relation][1]. Leave the builing ways as-is, but remove the tags fron the apron way (except maybe source=Bing for example) and put them in a relation. So that you do not have extra ways, yet the data is semantically correct. If two nodes are conceptually at the same location, then they should be a single node. Having "overlaping nodes" is dirty and unnecessary. Overlaping ways are more subjective : They are arguably dirty too but they can be oh-so-pratical. Using relations for the same purpose often sound like too much work. I use relations for complicated stuff, and overlaping ways for simpler ones. YMMV. In any case, overlaps/relations should only be used if the real-life objects actually "touch". A forest alongside a lake or an administrative boundary following a road/river are good examples, but a park alongside a forest road most certainly isn't (unless the road is mapped as an area). Said differently, only glue ways together if they are both areas/2D or both lines/1D, but not if you have a mix. [1]: http://wiki.openstreetmap.org/wiki/Multipolygon

In the case of the airport apron, a cleaner option is to use a [multypolygon relation][1]. Leave the builing ways as-is, but remove the tags fron the apron way (except maybe source=Bing for example) and put them in a relation. So that you do not have extra ways, yet the data is semantically correct. If two nodes are conceptually at the same location, then they should be a single node. Having "overlaping nodes" is dirty and unnecessary. Overlaping ways are more subjective : They are arguably dirty too but they can be oh-so-pratical. Using relations for the same purpose often sound like too much work. I use relations for complicated stuff, and overlaping ways for simpler ones. YMMV. In any case, overlaps/relations should only be used if the real-life objects actually "touch". A forest alongside a lake or an administrative boundary following a road/river are good examples, but a park alongside a forest most certainly isn't (unless the road is mapped as an area). Said differently, only glue ways together if they are both areas/2D or both lines/1D, but not if you have a mix. [1]: http://wiki.openstreetmap.org/wiki/Multipolygon