Viewing layers based on time

When analyzing a route database, it is sometimes useful to see what a route looked like at a given point in time and compare that to how it looks today. When the roadway changes shape, other aspects of the routes may also change. A state route that followed local roads for part of its life cycle would have much different roadway characteristics than that same route after it was merged with a freeway. If a crash was reported against that particular section of roadway in approximately the same time frame as the redesignation occurred, it would be important to know whether that crash occurred on the local road or on the freeway.

Esri Roads and Highways provides the ability to look at your routes system at any point in time to see what it looked like then, or will look like at a future date when planned roads become open to traffic. This is done by setting the time view for LRS layers. You can set the TVD for Network, Calibration Point, and Event Layers. Refer to Time-aware LRS to learn more about temporality in the advanced linear referencing system (ALRS).

The image below shows a route the way it looked in November of 2011.

NY5 before realignment

During a long construction project, a small portion of NY5 was coincident with I-90 and I-790. Following the construction of a ramp, NY5 was rerouted to surface streets at the I-90/NY8 interchange.

NY5 after realignment

To analyze the change, it is useful to display both the before and after views of the routes simultaneously. Here are the steps to set the TVD of a layer.

Steps:
  1. Start ArcMap and add an LRS Network to your map.
  2. Symbolize the network the way you want it by changing line weight, line style, and color and adding labels.
  3. Right-click the network in the ArcMap table of contents (TOC) and click Properties.

    The Layer Properties dialog box appears.

  4. Click the ALRS tab and ensure that the Always use current system date and time option is chosen.
    ALRS tab on Layer Properties dialog box
  5. Close the Layer Properties dialog box.
  6. Add the same network to the map again.
  7. Right-click the new instance of the network and click Properties.
  8. Click the ALRS tab and set the TVD to a date prior to an alignment change.
    TVD set to prealignment date
  9. Click the Definition Query tab and create a definition query for the specific routes you want to analyze.
    Definition query for NY5
    NoteNote:

    Ensure that you do not overwrite the TVD query.

  10. Click the Symbology tab and set the display symbol so your historical alignment will stand out.

    Set the historical layer symbol so it will stand out
  11. Click OK.

    Your historical layer displays with your current routes.

    Historical layer with current data
  12. When routes are concurrent, it is often useful to add just the changed route with the current date so the new alignment becomes more obvious. Add the same network to the route once again.
  13. Verify the TVD is set to the current system date and time.
  14. Create a definition query for your route.
  15. Set the symbology so your changed route will stand out.

    You can now see exactly how the new construction impacted the alignment of the routes.

    Visualization of change in routes
    NoteNote:

    You can also change the TVD of all the network and event layers and the Calibration Point layer present in the ArcMap TOC by using the Set Date Filter tool Set Date Filter on the Roads And Highways Editing toolbar.

    The Roads and Highways Editing toolbar

    Setting the TVD for multiple layers

    You can remove all TVD definition queries from your layers by clicking Clear definition filter for all LRS layers on the Set Date Filter dialog box.

    When using temporal data with time-enabled ArcGIS tools, such as thetime slider, all TVD definition queries must be removed from your layers prior to using these tools. When using temporal data with the Roadway Characteristics Editor, all TVD definition queries must be removed from your layers prior to publishing your map service. To learn more about deploying the Roadway Characteristics Editor, see the Overview of the Roadway Characteristics Editor deployment guide.

10/14/2014