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<p class=MsoNormal><font size=2 face=Arial><span lang=ET style='font-size:10.0pt;
font-family:Arial'>The pgDijkstra algorithm assigns to each RoadSegment a
unique EdgeID in graph. While assigning EdgeID, it expects that road segment
start and end point to be unique.&nbsp; This worked fine for our sample data (a
small area of Basingstoke) but in London some road segments have the same start
and end point (with a number of additional points in the middle which are
different).<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=ET style='font-size:10.0pt;
font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=ET style='font-size:10.0pt;
font-family:Arial'>For example two distinct road segments: <o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=ET style='font-size:10.0pt;
font-family:Arial'>LINESTRING(<b><span style='font-weight:bold'>524107.31
185330.493</span></b>,524106.899 185325.348,524112.444 185319.119,<b><span
style='font-weight:bold'>524118 185318</span></b>)<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=ET style='font-size:10.0pt;
font-family:Arial'>LINESTRING(<b><span style='font-weight:bold'>524107.31
185330.493</span></b>,524111.088 185329.479,524111.761 185329.298,524117.382
185322.233,<b><span style='font-weight:bold'>524118 185318</span></b>)<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'><o:p>&nbsp;</o:p></span></font></p>

<p class=MsoNormal><font size=2 face=Arial><span lang=EN-US style='font-size:
10.0pt;font-family:Arial'>What can we do to overcome this problem?<o:p></o:p></span></font></p>

<p class=MsoNormal><font size=1 color=teal face=Arial><span lang=FR
style='font-size:9.0pt;font-family:Arial;color:teal'>--------------------------<br>
Graham McConney</span></font><font size=2 face=Arial><span lang=EN-US
style='font-size:10.0pt;font-family:Arial'><br>
---<br>
</span></font><font size=1 face=Arial><span lang=EN-US style='font-size:7.5pt;
font-family:Arial'>Email scanned for viruses</span></font><span lang=EN-US><o:p></o:p></span></p>

<p class=MsoNormal><font size=3 face="Times New Roman"><span lang=EN-US
style='font-size:12.0pt'><o:p>&nbsp;</o:p></span></font></p>

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