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Part of my job is to analyze certain portions of road for our clients. A client will ask, I want to look at Road A from parcel XYZ to parcel RST and Road B from parcel RST to parcel OPQ.

The way I do this currently is:

  1. I select the road line layer around the parcels
  2. Save the selection as a new shp layer
  3. edit, trim, the layer as needed
  4. produce a new shp that matches the client's request.
  5. We analyze the hell out of the road

The reason I do selection/save as is that, in future when road geometry changes we will still have the original requested road. The problem I find with this is that by the end of the year, i have 100+ mini layers of road segments.

What are the issues in my process, and how can I improve on them?

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Do you have to save the selection as a new shp layer as opposed to just adding each section to one history layer? – Seth P. Jan 7 '11 at 15:25
@Seth P. - yes, as sometimes the road segments extend beyond the parcel – dassouki Jan 7 '11 at 15:28
Ok, but if you had a history layer that matched the extent and spatial reference for your parcels layer, you could copy the line segments to that layer and they would always fall within the extent. You could track which segment you want to analyze by recording it's insert date. – Seth P. Jan 7 '11 at 15:44
so you're saying i should linear reference my road selection to a a timestamped road layer based on versioning? – dassouki Jan 7 '11 at 16:43
That makes sense to me. If I follow Seth's reasoning, you would be creating snapshots of the road network for a specific period of time that include all analyzed road sections. Would this not save space and time when having to fetch the data at a later date? – Nathanus Mar 4 '11 at 18:41

This is an old White Paper from Esri in April 2003 on Linear Referencing in ArcGIS®: Practical Considerations for the Development of an Enterprisewide GIS but in it, on pages 10-11, Managing History is discussed, and I think the advice it offers still holds today:

Use of effective time in linear referencing applications is critically important. For example, imagine a scenario in which a road realignment was finished on January 10. Now imagine that a traffic accident occurred on January 21. Users need to locate the traffic accident against the state of the network on January 21. The ArcGIS system and geodatabase support these scenarios through historical versioning.

Certainly, if I had your requirement, and access to Enterprise Geodatabase licensing, then it is Historical Versioning that I would investigate as a way to improve upon your current process.

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