Gerhard, Thank you for posting this . I'm just away to look at it. I am studying for a PhD that is based on routing algorithms. At present I have a MYSQL copy of the Openstreetmap data for Edinburgh that I am using for this. I certainly have issues with the accuracy of this data that is causing issues with routing. Ways that are not connected to an others are certainly an issue. I was just about to come onto the forum to post about it when I saw your post...
One of the other issues that I have are Ways that appear to have extra nodes on them that I do not understand why they are there. I'm assuming that they are errors but I wanted to double check first... For example there is a road called Charles Street in Edinburgh way id =7972092. This way has 4 distinct nodes but the last one is repeated so that a routing algorithm moving along the street would move from node id= 287241490 to node id=287241490. I'm assuming that the above example is an error. There seems to be plenty of them too. In the Edinburgh area I have identified about 100. Some of them are completely unnecessary Ways. For example Blacket Place is represented by two ways. the first id=27992340 appears to be valid. The other way id=4048677 consists of one node(id=307349548) 12 times! Of course I could code any routing algorithm to ignore these 'null' moves but I was wondering;- a) How do these errors get there? Can validation checks be added when ways are created/updated? b) Have you found an issue with these errors or are you just coding to ignore them? Thanks, Cathy ________________________________________ From: [email protected] [[email protected]] On Behalf Of [email protected] [[email protected]] Sent: 31 December 2008 12:00 To: [email protected] Subject: Routing Digest, Vol 16, Issue 9 Send Routing mailing list submissions to [email protected] To subscribe or unsubscribe via the World Wide Web, visit http://lists.openstreetmap.org/listinfo/routing or, via email, send a message with subject or body 'help' to [email protected] You can reach the person managing the list at [email protected] When replying, please edit your Subject line so it is more specific than "Re: Contents of Routing digest..." Today's Topics: 1. Errors in map data that affect correct routing - and what to do about it... (GS) ---------------------------------------------------------------------- Message: 1 Date: Wed, 31 Dec 2008 10:10:51 +0000 (GMT) From: GS <[email protected]> Subject: [Routing] Errors in map data that affect correct routing - and what to do about it... To: [email protected] Message-ID: <[email protected]> Content-Type: text/plain; charset=utf-8 hi, from time to time people encounter errors in routes or destinations can't be reached. there are a lot of reasons for this. and a lot of reasons can be found in the output of my check programs. so if you no longer want to do "trial and error" and want to correct the map data proactively have a look at the programs and their outputs. waycheck looks for unconnected endpoints of ways and crossings of ways on the same layer where the ways don't share a common node. http://wiki.openstreetmap.org/wiki/WayCheck checkconn does the above mentioned check, but faster and with less memory. checkcross does the above mentioned check, but faster and with less memory. checktouch checks for endpoints of ways that nearly touch another way. so presumably these ways should be connected. motorwaycheck checks for invalid motorways (invalid oneway tags and possibly wrong directions of ways). http://wiki.openstreetmap.org/wiki/MotorwayCheck lots of reports can be found here: http://wiki.openstreetmap.org/wiki/DE:WayCheck all programs can also be found on my wiki page: http://wiki.openstreetmap.org/wiki/User:Gary68 generally there is a wiki page for quality assurance here: http://wiki.openstreetmap.org/wiki/Quality_Assurance cheers gary68 gerhard ------------------------------ _______________________________________________ Routing mailing list [email protected] http://lists.openstreetmap.org/listinfo/routing End of Routing Digest, Vol 16, Issue 9 ************************************** Napier University is the best modern university in Scotland* and number one in Scotland for graduate employability** (*Guardian University Guide 2009) (**HESA 2008) This message is intended for the addressee(s) only and should not be read, copied or disclosed to anyone else outwith the University without the permission of the sender. It is your responsibility to ensure that this message and any attachments are scanned for viruses or other defects. Napier University does not accept liability for any loss or damage which may result from this email or any attachment, or for errors or omissions arising after it was sent. Email is not a secure medium. Email entering the University's system is subject to routine monitoring and filtering by the University. Napier University is a registered Scottish charity. Registration number SC018373 _______________________________________________ Routing mailing list [email protected] http://lists.openstreetmap.org/listinfo/routing
