I have a shapefile in which a bunch of the lines are multipart. Sometimes this is due to joining ways that are not quite connected (gap less than a foot of real-world distance) and sometimes the endpoints of each part are at exactly the same place (thanks to snapping before joining).
This is really annoying because it means that splitting does not work properly, among other lesser problems.
I've tried every suggestion I've come across. GRASS v.clean.snap with tolerance 1 does nothing. Exporting to KML and removing the gaps in the KML file works but only if the parts are in the correct order and direction (otherwise I get garbage connecting lines). Exporting to GPX completely fails because GPX can only handle single-part lines.
Am I missing something here? Why does this problem even exist? I understand why it happens when there is a slight gap, but I can't see any situation in which joining two topologically connected ways in a multipart line is a feature rather than a bug.
Here (click "Click here to start download from sendspace") is a shapefile with two multipart lines. I-85 has a tiny gap (at the state line), while I-795 connects perfectly yet has three parts. Does anyone have a solution for this, one that can be batch-applied to a file with many lines?