I have a line feature class that represents greenways and trails. Many of the trails have been mapped with a recreation grade GPS. As more GPS tracks or new aerial photos become available, I ‘refine’ many of the line features using the following steps:
1) Split the line in two places: at the start and at the end of where I need to redigitize the line
2) Select the line segment that is to be deleted
3) Delete this line segment
4) Redigitize the line segment with the more accurate alignment
5) Merge the redigitized portion with the portions of the original line that were not redigitized
Although the resulting line is one feature, the order of the vertices often becomes very fragmented. This may seem inconsequential, but it has repeatedly caused the following problem. In step 2 above portions of the line that are far from the segment am redigitizing are inadvertently selected. See the attached jpeg for an example. The selected feature is one feature. These unintentionally selected line segments are often off the screen. When I delete the portion that I intend to delete, the portion that’s off the screen can be deleted accidentally. Yes, I can and should be more careful by verifying that that only the portion I intend to delete is selected. But there are other reasons why I would like to have cleaner lines.
This line feature class is stored in SDE, so the Check Geometry tool is futile. Dissolve probably isn’t a good approach because I need the trails to remain individual line segments at intersections – we may use these lines in a routing scenario some day. Create Routes drops the attributes and I don’t want to deal with M values – linear referencing is not needed here.
Suggestions?
Hi Alex, not exactly sure if there is one particular element of your workflow that you would like feedback on or the entire thing? If you are trying to solve the issue of accidentally deleting a multi-part line then I might suggest adding two steps to your workflow (below).
1) Split the line in two places: at the start and at the end of where I need to redigitize the line
2) Select the line segment that is to be deleted
3) Exploded multipart (Advanced Editing Toolbar)
4) Reselect the line segment(s) to be deleted
5) Delete this line segment
6) Redigitize the line segment with the more accurate alignment
7) Merge the redigitized portion with the portions of the original line(s) that were not redigitized
If you are more interested in preparing your data for routing then one step would be creating and maintaining intersections. You could use XTools Create Intersections for this step. With intersections created you could add more processing steps like Unsplit Lines (merges lines with coincident endpoints), Integrate (ensures lines are snapped within defined tolerance), and Split Line by Point (split lines by your intersection points to recreate your line segments between intersections) to ensure your lines are clean, snapped, and ready for a network to be built.
Good luck and hope this is helpful.
Thanks, Ben. The explode suggestion is a good idea. It's somewhat similar to using the 'zoom to selected features' to verify that I'm aware of every part of the fragmented that is selected. I just have to remember to do either one with each edit.
It'd still be nice to have an easy way to "clean" the line so that all of the vertices are are in the order that you would expect. It'd be even better if one could specify an edit mode that would reorder vertices at the end of every merge. This fragmented ordering makes me a bit uneasy to think about how these lines will appear if I ever need to export them to a different format.