2

Below are the steps to find the shortest route between two points in a road network https://docs.qgis.org/2.18/en/docs/training_manual/vector_analysis/network_analysis.html

Is it possible to find the shortest route using the road network, but from a point feature where the point doesn't sit on a road, to the nearest road and follow the shortest route to a point on another feature? So three features, initial start point, road and end point.

If so, can this be done for multiple routes that all end up at the same end point? So the start point feature will have many points, and follow the shortest routes to one endpoint.

  • You are using a pretty old reference there. In general, it is possible, but you won't be using network analysis for the first part, and under some circumstances "closest" might be bogus (like not being able to get across a ditch or fence to access the road even though that would be the shortest distance if it was possible). What have you tried? – BradHards Oct 23 '17 at 5:32
  • the docs.qgis.org/2.18/en/docs/training_manual/vector_analysis/… is the same as 2.2. please can you edit your post to give recent reference instead of the old one – Hugo Roussaffa - GeoDatup Oct 23 '17 at 7:42
  • Welcome to gis.stackexchange! Please note that each thread should be limited to one specific question only. You can check our tour for more information. – underdark Oct 24 '17 at 16:53
1

This is possible in QGIS 3.0. The processing toolbox in 3.0 has told for running shortest path analysis based on various combinations of source and destination point layers.

  • OK thanks. I'll wait until it is available as 2.18 is still only available. – Joshua J Geoghegan Oct 23 '17 at 21:56
  • Do we have a date on when this will be available to download? – Joshua J Geoghegan Oct 23 '17 at 22:04
  • You can download a weekly release now, it's definitely usable for analysis tasks like this. Don't use it as a daily workhorse though, since the project format may change between now and release. – ndawson Oct 24 '17 at 0:48
  • When running the shortest path tool I am getting an error. Maybe this is a bug? Building graph... Traceback (most recent call last): File "C:/PROGRA~1/QGIS2~1.99/apps/qgis-dev/./python/plugins\processing\algs\qgis\ShortestPathPointToPoint.py", line 213, in processAlgorithm snappedPoints = director.makeGraph(builder, [startPoint, endPoint], feedback) Exception: unknown Execution failed after 0.74 seconds – Joshua J Geoghegan Oct 24 '17 at 22:19
  • Can you file a ticket on issues.qgis.org with a copy of your data and I'll look? – ndawson Oct 25 '17 at 0:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.