Dear Jack,
There are issues about representation and the scale of measurement that
need to be regarded when you use the road-centres line as your base model.
For segment analysis these issues are minimised due to the type of
measurement (angular turns) used. However, you would expect some margin of
error. If you are covering a small area, say, within a radius of
3000meters you might need to manually adjust your map and simplify it. If
you are covering large areas you might just ignore the error and run your
analysis.
One of the main advantages of angular segment analysis is ability to use
road-centres line data. For reference see (Dalton, et. al., 2003);
http://eprints.ucl.ac.uk/1109/1/TTT.pdf.pdf
Researchers have safely used road-centres lines (ITN networks) in regional
scale segment analysis. See (Turner, 2009)for reference on that;
http://www.sss7.org/Proceedings/09%20New%20Modes%20of%20Modelling%20and%20Methodological%20Development/116_Turner.pdf
A paper has also been recently presented in Space Syntax symposium on the
performance of ITN network and axial representations in segment analysis.
See (Dhanani et. al., 2012);
http://www.sss8.cl/media/upload/paginas/seccion/8211.pdf
All the best,
Kinda
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Kinda Al_Sayed
UCL Teaching Fellow
email: [log in to unmask]
> I am interested in creating a segment map of a street network using
> road-center lines. The original lines came from an ArcGis shapefile and
> are segmented at junctions. I've imported them into Depthmap as a DXF. My
> question is can i turn the imported DXF(segmented lines) into a segment
> map immediately or do I need to first create a least line axial map first?
>
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