Realigning a route using multiple source geometry features

Sometimes you have more than one source geometry feature to realign an existing route. This is often the case when source geometry comes from computer-aided design and drafting (CADD) files or other sources outside of the GIS team. Using multiple source geometries can cause problems for route calibration, especially when some of the features are not contiguous.

The Roads And Highways Editing tools seamlessly detect when you use more than one single source geometry feature.

Esri Roads and Highways supports the following geometry selections:

• Multiple segments from one source geometry feature
• Multiple segments from multiple source geometry features

Steps:

1. Start ArcMap.
2. Add the necessary layers to begin an edit session.
3. Zoom to the location of your new route.
4. Optionally select a redline feature.
5. Select the source geometry features.

   You can press and hold the SHIFT key and draw a bounding box to select or deselect source geometry features. The features are labeled on the map based on the order of selection. You can opt to select multiple source geometry types, including CADD, shapefile, or feature class.

   Note:

   If you draw a bounding box around multiple features, the labels may not be in sequential order.

   The selected source geometry features are highlighted on the map. A label is placed in the center of the feature to let you know the sequence of the realigned route.

6. Click the Apply button .

   The Realign Route dialog box appears. Values on the Realign Route dialog box are auto-populated from the selected redline. Skip ahead to step 7.

   If you did not select a redline or the redline was missing attributes, the parameters on the Realign Route dialog box need to be manually entered.

   1. Enter an effective date for the alignment:
      • Manually enter a date in the Effective Date field. Acceptable date formats include M/D/YY, MM/DD/YY, or MM/DD/YYYY.
      • Click the calendar drop-down menu and select the alignment date from the calendar.
   2. Enter a Route ID.
   3. Enter the parameter From Measure:
      • Manually enter a From Measure.
      • Click the Select From Measure tool and click the map at the location of the from measure.
      • If you do not know the From Measure, you can let Roads and Highways suggest the From Measure. The From Measure is calculated as the source geometry length minus (-) the To Measure.
        1. Enter a parameter To Measure.
        2. Click Calculate.
   4. Enter the parameter To Measure. There are many ways to calculate the To Measure as outlined below:
      • Manually enter a To Measure.
      • Click the Select To Measure tool and click the map at the location of the from measure.
      • If you do not know the To Measure, you can let Roads and Highways suggest the To Measure. The To Measure is calculated as the source geometry length plus (+) the To Measure.
        1. Enter a parameter To Measure.
        2. Click Calculate.
   5. Enter the split From Measure:
      • Manually enter a From Measure.
      • Click the Select From Measure tool and click the map at the location of the From measure.
   6. Enter the split To Measure:
      • Manually enter a To Measure.
      • Click the Select To Measure tool and click the map at the location of the To measure.
7. Verify the Effective Date, Route ID, From Measure, and To Measure parameters of your new alignment are correct.
8. Determine whether you want to recalibrate your route downstream and check or uncheck the Recalibrate route downstream check box as appropriate.

   Roads and Highways assumes that the measure values you enter take precedence over the measure values that already exist on the route. This can create an undesirable effect if the measure values entered create logical gaps or overlaps in route measures. In our example, the from measure of the redline feature is less than the measure of the actual location the original route will be split.

   By permitting this, we are saying that location 15.9126 has an incorrect value and the real measure at that location should be 15.5908. This is common since roads are often remeasured when a new alignment is added. Roads and Highways places a calibration point at the intersection of the new and original alignments and adjusts measures along the route the first calibration point encountered prior to the realignment. Events follow their Calibrate Route behavior.

   If you choose not to calibrate downstream, you may run into even more issues when logical gaps or overlaps are created, since downstream measures are not allowed to change. By choosing not to recalibrate downstream, you are overriding the derived measures of the route. Some calibration will happen to your route in the immediate vicinity of the realignment, however, because failure to recalibrate could otherwise break the rule that routes must have strictly increasing or strictly decreasing measures. The following rules are applied when you realign without downstream calibration:

   • If the to measure of the new alignment is less than the split measure, the route calibrates using the new alignment length up to the split location. The original measures are used from the split location on. In our example, with a to measure of 16.3168 and a larger split measure of 16.5909, two calibration points are placed at the intersection, and there is no physical geometry for a measured length of 0.274 miles.
   • If the to measure of the new alignment is greater than the split measure, the route is recalibrated to the first downstream calibration point encountered. All subsequent measures are retained. Events between the new alignment and the first calibration point follow their Calibrate Route behavior.

9. Click OK.

   NY49 after realignment