Routes are calibrated using point features named calibration points. Calibration points are edited using ArcMap editing tools. ArcGIS Roads and Highways uses the modifications made to calibration points to recalibrate the routes. To modify the path of a route, use the ArcGIS Roads and Highways editing activities (for example, extend route, retire route, realign route, or reassign route). To change the calibration or measure values on a route, but not the path of the route, you can edit the network's calibration point feature class. This calibration point feature class can be edited using ArcMap editing tools and the calibration point tools on the Roads and Highways toolbar to add a new calibration point, edit an existing calibration point, or delete a calibration point. Roads and Highways will reflect these changes by updating the calibration (or measures) on the route.
Calibration points drive the calibration of a route and can override the digitized direction of centerlines. If you add, modify, or delete calibration points, you are telling ArcGIS Roads and Highways explicitly what a measure value is at a specific location 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 vary depending on the distance between your calibration points. To ensure that calibration stops at a specific location before or after the calibration point being modified, add a new calibration point at that location to lock the calibration in place.
Calibration points are time aware; 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 value of null means the calibration point has been effective since the highway was first created. A null To Date value 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.
The following topics describe how to manage calibration points:
- Adding calibration points using the Roads and Highways Editing toolbar
- Adding calibration points using ArcMap editing tools
- Retiring calibration points
- Moving calibration points using ArcMap editing tools
- Modifying calibration point measure values and temporality using the Roads and Highways Editing toolbar
- Modifying calibration point measure values using ArcMap editing tools
- Deleting calibration points