[GRASS-user] Correcting Junctions

[Dennis Scheck]

Dear all:

I have two vector maps, one with road segments, and one with junction
points. But I know the Junctions aren't 100% correct. Sometimes there are
intersecting road segments.

I want to find out which nodes in the junctions map are unnecessary (if 
any), and which are missing.

How can I accomplish that? Any help appreciated.

My approaches so far were to use v.net (nodes) on the road segments to
create correct segments and nodes in a new layer. My understanding is that
the new layer now contains correct nodes and line segments.

Then I tried to use v.overlay to find nodes in my nodes map that overlap
nodes in the newly created map. But the result was empty.

I also tried to use a SQL Query on the new map to select all "cat" that
aren't in the junction map, but that didn't work either.

I'm quite new to grass, and unfortunately I'm stuck now. Could you please
give some advice? 

Thanks in advance
Dennis