1/24/2011 10:55:10 AM
carol birchall
Posts: 17
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Can anyone tell me when calculating road based journeys does Accession take grade separated junctions into account and not allow trips to transfer from one link to another at these points. Or do I still have to join links together to make sure that this doesn't happen?
Carol
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1/24/2011 11:05:48 AM
admin
Administrator
Posts: 146
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Hi Carol,
What type of Road Network have you been using? ITN data includes Grade Separation - so Accession will not allow transfer onto a motorway where there is a bridge/tunnel etc,
Regards,
Dan
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2/2/2011 1:43:56 PM
carol birchall
Posts: 17
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Hi Dan, I am using ITN so should be alright then.
Thanks
Carol
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2/2/2011 2:51:13 PM
carol birchall
Posts: 17
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Addendum!
Dan I have just created a 'clipped' ITN network, simply by drawing a rectangle, and the grade separation details have not copied across, these nodes appear in the legend as 'no attributes'. Any clues?
Carol
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2/2/2011 3:01:37 PM
admin
Administrator
Posts: 146
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Hi Carol,
This is strange, the road clipping tool should copy across all the attributes. How large was the road network before cutting and have you cut the network by much?
Regards,
Dan
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2/3/2011 3:00:58 PM
carol birchall
Posts: 17
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Hi Dan,
Sorry for the delay in getting back to you ... just wanted to do a few quick checks.
The issue I flagged was based on the legend that comes up with the cropped network when compared with the one for the original uncropped one - see attached pdf's.
So where on the legend for the original network there are four types of RoadNodes (No attributes; Mini-Roundabout; Grade Separation and Other), on the cropped one there are just two (No attributes and Other). However, having run walking & cycling calculations using both networks, they appear to give the same results, certainly the contours produced are identical. Does this mean then that the problem is with the legend and not actually with the node attributes do you think?
The original uncropped network is composed of two ITN tiles ie roughly 50km x 25km, the cropped version is roughly about half that ie 25km x 20km.
Thanks
Carol
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2/3/2011 3:48:36 PM
admin
Administrator
Posts: 146
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Hi Carol,
This is strange as the crop has bought across all of the other attributes like turn restrictions but not the grade separation. The identical results could just be a red herring, I personally would not trust the cropped network, I will report this to Citilabs to investigate.
Regards,
Dan
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2/3/2011 4:06:21 PM
carol birchall
Posts: 17
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Okay, Dan.
Thank you.
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2/9/2011 1:40:13 PM
RobT
Posts: 36
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Hi Carol,
I have found that in the most recent edition to Accession there has been a few issues with nodes in general, I can no longer access junction editor? Could it be linked with this?
Rob
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2/9/2011 2:03:02 PM
carol birchall
Posts: 17
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Hi Rob,
I have only just really started to use a road network to look at walking and cycling so please excuse my ignorance but I didn't realise that there was (or should be!) a junction editor, so I can't tell you if it is working or not! How or where should I be able to access this? I have tried right clicking on a node but this just brings up the 'road link details' option. I can't find anything in the original user guide and unfortunately 'Help' isn't working either.
Dan, can you shed any light on this?
Cheers
Carol
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2/9/2011 2:59:10 PM
admin
Administrator
Posts: 146
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Hi Carol.
In the previous version you could right click on a road node and get Junction editor, though in the current version this has seemed to have disappeared. The two could be linked, I will fire it off to Citilabs.
Dan
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2/10/2011 11:46:32 AM
carol birchall
Posts: 17
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Do you think that Accession is taking account of the node attributes in calculations, is it just the node editing function that is not there? Or do you think that any calcs using a road network could possibly be suspect?
Carol
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2/11/2011 9:33:44 AM
admin
Administrator
Posts: 146
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Hi Carol/Rob,
Will do some tests this morning and report back,
Regards,
Dan
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2/11/2011 4:23:37 PM
admin
Administrator
Posts: 146
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Hi Carol,
Having had a play with the software, turn restrictions are used both when a network is cut in Accession and by default, it just seems accessing the junction editor has been disabled.
Regards,
Dan
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