Editing Large-Scale Objects
While OpenStreetMap has an impressive data quality on small scale objects, large scale objects are often only mapped in low quality. One example is the often discussed subject of mapping public transport services, and indeed these are far from complete or consistent.
The deeper reason for this is that editing large scale objects is exceptionally hard: This results from the fact that the larger an object is, the more spatial dependencies it is involved in. For example, a public transport relation can be damaged by each and every roundabout or lane mapping attempt.
In this talk we will analyse which typical kinds of dependencies exist and discuss various approaches like route suggestion by involving a route engine or mapping on a filtered subset of data. As a hands-on example it is shown how to efficiently recover a lost name tag on the river Rhine by editing an area of more than a hundred kilometers extent in JOSM.