Calibrating a route

When routes are calibrated, calibration points are given priority over everything else, including the digitized direction of centerlines. If you add or modify your calibration points, you are telling Esri Roads and Highways explicitly what a measure value is at a specific location.

Note:

This will override any interpolation of measures already existing on the route.

Route recalibration is only impacted by calibration points that have changed. The route will be recalibrated between the two calibration points to either side of the calibration point being changed. The results you see will be different depending on how far apart your calibration points are. If you want to ensure that calibration stops at a specific location before or after the calibration point being modified, add a new calibration point at that spot to lock the calibration in place. If you want to recalibrate a large section of roadway, select all existing calibration points on that section of route and retire them when you place your new calibration points.

Calibration points are time aware, which means they respect time. This means that route calibration on a highway may change over time. When adding or modifying a calibration point, be sure to apply a time period for when that calibration point is active by setting the From Date and To Date fields. A from date of null means the calibration point has been effective since the highway was first created. A null to date means the calibration point is expected to continue to be valid into the foreseeable future.

To properly locate events along routes, Roads and Highways expects calibration points to have strictly increasing or strictly decreasing measure values along the routes. Although Roads and Highways does not prevent you from doing so, adding calibration points with measures out of sequence will improperly calibrate the route, and event data may not display properly. By applying calibration, you also cause event data to be updated. If you improperly calibrate a route by setting out-of-sequence measure values, event data with Stay Put or Snap behavior may be incorrectly updated.

Recalibrating a route can have a significant impact on business data. You should not recalibrate routes or modify calibration points unless you are fully aware of the consequences. You should avoid modifying existing calibration points other than the effective date. In most cases, you should retire rather than delete obsolete calibration points.

In this topic you will learn how to do the following:

• Add calibration points
• Retire calibration points
• Move calibration points
• Modify calibration point measure values
• Delete calibration points
• Save route calibration

Adding calibration points

Roads and Highways listens for edits made in the calibration point feature class. If you add a new calibration point, Roads and Highways will attempt to apply the new calibration to whatever route it references.

See Adding new calibration points along routes using the ArcMap editing tools for more information on adding calibration points.

Steps:

1. Add a new calibration point feature by snapping to your route.
   • Create a point by copying and pasting an existing point.
     Tip:

     Copying and pasting is the easiest way to add new points. This can be done by copying an existing calibration point along the same route, moving it, and modifying its attributes, or by copying calibration points from a shapefile or other feature class and pasting them into the calibration point feature class.

   • Create a point at an exact x,y location.
   • Create a point at the end of a line you sketch.
   • Create a point at a distance and direction from a specific location.
   • Create a point at the intersection of two distances.
   • Create a point at the intersection of two segments.
   • Create a point at the midpoint of two locations.
2. Update the attributes of the new calibration points.
   1. Give the point a route ID.
   2. Specify the LRS Network ID.
   3. Assign a measure value.
   4. Set the from date of the calibration point.
   5. Optionally give the calibration point a to date if you know when it was or is expected to be retired.
   6. Optionally give the point a calibration point ID.
3. Click the Apply Calibration Point Edits button .

   The route is recalibrated by regenerating its shape based on the updated calibration points and its measures, and event data is updated based on the event layers' Calibrate Route rules.

Retiring calibration points

Calibration points can be retired when they are no longer relevant. This is the preferred way to modify calibration points. The original calibration point should be retired by modifying its to date, and a new calibration point should be added with updated measure values and/or location information and a from date set to the effective date of the change in the route calibration.

Steps:

1. Select a calibration point.
2. Change the To Date attribute to the effective date of the recalibration.
3. Click the Apply Calibration Point Edits button .

   The existing calibration point will be retired effective as of the calibration point's to date. The route is recalibrated by regenerating its shape based on the updated calibration points and its measures. If you set the temporal view date (TVD) of the LRS Network to an earlier date, you will see the route calibration as it was at that time. Event data will be updated according to each event layer's Calibrate Route rules.

Moving calibration points

Routes can also be calibrated by moving calibration points from one location to another along a route.

Caution:

Calibration points should only be moved if you want the change to be effective for the entire life span of the calibration point. The preferred method of recalibrating is to retire the original calibration point and add a new one. That way, when you look at a previous version of the highway, you will see event data based on how the highway was calibrated at that time. See Advanced linear referencing-Time-aware LRS to learn more about temporality in the advanced linear referencing system (ALRS).

Steps:

1. Select a calibration point using the Edit tool on the Editor toolbar.
2. Drag the point along the route and drop it in a new location.
3. Verify route ID, network ID, and measure attributes.
4. Click the Apply Calibration Point Edits button .

   The route is recalibrated by regenerating its shape based on the updated calibration points and its measures, and event data is updated based on the event layers' Calibrate Route rules.

Modifying calibration point measure values

Another way to recalibrate a route is to change the measure value of an existing calibration point.

Caution:

Calibration point measure values should only be modified if you want the change to be effective for the entire life span of the calibration point. The preferred method of recalibrating is to retire the original calibration point and add a new one.

Steps:

1. Select a calibration point.
2. Edit the measure value.
3. Click the Apply Calibration Point Edits button .

   The route is recalibrated by regenerating its shape based on the updated calibration points and its measures, and event data is updated based on the event layers' Calibrate Route rules.

Deleting calibration points

Routes can also be calibrated by deleting calibration points.

Caution:

Deletion of calibration points is not recommended. To preserve the historical integrity of the route, obsolete calibration points should be retired instead.

Steps:

1. Select a calibration point.
2. Press the DELETE key.
3. Click the Apply Calibration Point Edits button .

   The route is recalibrated by regenerating its shape based on the updated calibration points and its measures, and event data is updated based on the event layers' Calibrate Route rules.

Saving route calibration

Route calibration is not fully implemented until you save your edits. If you don't save, you can always undo your changes or stop editing without saving changes to roll your calibration back to its previous state. If you choose to save your edits, however, your recalibration will be applied. Since the Roads And Highways Edit Tools toolbar is stateless, you can click any other button on the map while the tools are active. This means that you can potentially save your edits without applying your calibration point edits. Roads and Highways is aware that calibration points have been edited, however, and gives you a chance to apply the event behavior when you save edits.

Steps:

1. Edit calibration points.
2. Click the Save Edits button on the Production Editing toolbar or the Editor menu on the Editor toolbar.

   A warning appears indicating that calibration points have been modified.
3. Decide what to do with the calibration.
   • Click Yes if you want to apply the route calibration to event layers.
   • Click No if you do not want to apply the route calibration to event layers.

   You cannot interrupt a save operation. Once the Save Edits button has been clicked, your updates will be saved regardless of whether you choose to apply the recalibration. Clicking No merely prevents event data from being updated. As a result, all of your event layers will follow Move behavior and x,y references may be lost.