I am attempting to generate drive time polygons that span state lines. Is there a way to join road segments that span the state boundary - e.g. how do I create a national road network whereby a rural road the crosses the NC-VA border is recognized as one road segment. asked 25 May '16, 14:31  ARM2020 |
One Answer:
In general, such roads should be connected in OSM (which just means that they share a node). There is a possibility that your data processing is somehow dropping these connections. One way this could happen is converting several OSM extracts into whatever format you are using for processing. So if you are seeing many missing connections you may want to investigate whether your pipeline is setup to preserve the connections. If it is only a few missing connections, check to see if the modeling is correct in the main OSM database. answered 25 May '16, 14:38  maxerickson |
It seems that the roads are connected, but on different ways (i.e. sharing the connecting node, which sometimes also lies on the state border): e.g. here, the roads are obviously mapped as different types on each side of the border: https://www.openstreetmap.org/relation/224045#map=16/36.5444/-78.1401
It appears on the Virginia of the example that is a state highway while on the North Carolina side, it is just a regular ol' county road. This is typical when crossing state lines. Often times when you're riding along at the state border, you'll feel quite a thunderous bump and the road will either be much better or worse depending on the side you're on.