I'm trying to perform an OD Cost Matrix calculation on a set of points using a road network from OpenStreetMap data. The network contains lots of roads that don't connect to the rest of the network. In the case where a point snaps to such a place on the network, it can't reach any other sample points.
How do I remove these sections of road? Or if that's not possible, how could I systematically identify those areas and connect them to the rest of the network?
Answer
My solution to this was kind of a kludge, but then I was doing a small class project working with a subset of one county's roads so the network wasn't that big and I didn't need to do it as a common task. I just ran a service area analysis with the time set large enough that in theory everything should be reachable. That highlighted everything that was connected, thereby showing what wasn't. Some of them I added new connections because I needed to preserve those areas, others I simply selected and deleted the isolated roads from the dataset.
10.1 help has reference to a Find Disconnected tool on the Utility Network Analyst Toolbar if you have access to that.
10.2.1 also has a new tool that might do what you want, if you have access to that version or higher: Find Disconnected Features In Geometric Network (Data Management)
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