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I have two polygon feature layers: one representing land parcels and one representing roads. Some land parcels (polygons) coincide with a part of a road (another polygon feature). How can I check which land parcels coincide in any of their boundaries with a road? Of course help will be great if a code in VBA and ArcObjects is already available. I note also that I have considered the topology rules defined in http://webhelp.esri.com/arcgisdesktop/9.3/index.cfm?TopicName=Topology_rules and also and the ITopologyRule interface but I could not be sure which rule in both cases to use for solving my problem. Thanks. Demetris

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Just to note that I have solved the problem and my code works.As jufemaiz notes below "I would be rather surprised....if the road boundaries and the land parcel boundaries coincide". Indeed, some parcels while have access to roads they are not identified while many of them are identified. It seems that the problem is that they have to coincide very accurately. Anyway, this is a matter of screen digitisation and not a problem of the program. The program itself works very well. Of course, perhaps somebody could follow other methods to correct the parts parcels and roads are not coincide. –  Demetris Jun 14 '11 at 18:04

2 Answers 2

Take a look at the Select by Location dialog in ArcMap. You can try either selecting parcels that share a line segment with your roads or select parcels within a small distance from roads.

If you want to do it 'topologically' you would have to do it through code by building a topology graph then walking the parcel segments to see if the edge is shared with a road. The old VB6 sample 'topological queries' used to do this but it hasnt been updated for some time.

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Thanks. This is a good idea to have a look especially the "Touch the boundary of" option of the select by location operation that may work for my case. However, if somebody has a code in VBA and ArcObjects would be very appreciated. –  Demetris Jun 13 '11 at 18:43

This is definitely not going to be easy, for the particular reason that you're going to want to have this problem I have fully solved to determine point-in-polygon and then extend this to determine if there is a crossing of each polygon line segment.

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I have already used point in polygon programmatically successfully i.e. to check if a point falls within a polygon or not. However, my problem is different and surelly not a crossing problem. The boundaries of some land parcels (poolygon feature) coincide with the boundaries i.e. edges of roads (polygon feature) and I want to identify which land parcels have a fronatge on to a road. –  Demetris Jun 13 '11 at 16:10
    
Not all test cases can use the raytrace method without a further piece of information unfortunately - and it does become problematic when going over the +/-180degree mark. I would be rather surprised, having spent a good half decade working with GIS systems, that the road boundaries and the land parcel boundaries coincide. Much of the time the data quality doesn't allow for this - which leads to a question of proximity and accuracy that you have in your dataset. –  jufemaiz Jun 14 '11 at 0:02
    
Yes. This is also an issue raised but I need to try it first and then inform you about. –  Demetris Jun 14 '11 at 4:35
    
Please, have a look in the code I have added in the main part of the question. Help, is appreciated. –  Demetris Jun 14 '11 at 12:45
    
Hi @Demetris - I can't see code in this question. –  jufemaiz Jun 21 '11 at 1:58

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