Georeferencing Roadway Crossings (GeoSTORM)

When the GeoSTORM software imports a model, it automatically places the roadway crossings on the Map View. However, if the original model was not spatially georeferenced, the roadway crossings will not align with the loaded background base map. So, it is preferable to have the roadway crossings georeferenced to the background base map. In this scenario, the Georeference Roadway Crossings command of the GeoSTORM software can be used to manually georeference each of the roadway crossings to the background base map displayed on the Map View. Note that a CRS should be assigned prior to running this command. Otherwise, the software will display the informational dialog box, as shown below.

Refer to this article in our knowledge base to learn how to assign a coordinate reference system to a project. Follow the steps below to georeference an existing roadway crossing:

1. From the Input ribbon menu, click on the Roadway Culverts dropdown menu and then select the Georeference Roadway Crossings command.
2. The Georeference Roadway Crossings dialog box will be displayed, as shown below.

The following sections describe how to georeference an existing roadway crossing and interact with the above dialog box.

Selecting Roadway Crossing to Georeference

Follow the steps below to select the roadway crossing to be georeferenced:

1. Select the roadway crossing from the Roadway crossing ID dropdown combo box that lists all the roadway crossings contained within the project.
2. Alternatively, the user can click the [Pick] button to select the roadway crossing from the Map View. After clicking the [Pick] button, the Georeference Roadway Crossings dialog box will temporarily disappear, and a prompt will be displayed on the status bar instructing the user to select the roadway crossing from the Map View.
3. After selecting the roadway crossing, the user will be immediately returned to the dialog box, and the selected roadway crossing will be highlighted on the Map View. The user can click the [Clear] button to cancel the previous selection and redo the entire process.

Once the roadway crossing has been selected, the user can choose between the following options to georeference the roadway crossing:

• Snap to Alignment Polyline
• Slide Along Alignment Polyline
• Draw on Map View

Snapping Roadway Crossing to an Alignment Polyline

If an existing alignment polyline for the roadway crossing exists on the Map View, the Snap to Alignment Polyline georeferencing option can be used to snap the roadway crossing to the alignment polyline. Follow the steps below to use the Snap to Alignment Polyline georeferencing option:

1. Select the Snap to Alignment Polyline radio button option.
2. Click the [Pick] button next to the Select alignment polyline read-only field.
3. The Georeference Roadway Crossings dialog box will temporarily disappear, and a prompt will be displayed on the status bar instructing the user to select the alignment polyline.
4. After selecting the alignment polyline, the Georeference Crossings dialog box will be redisplayed and the status of the Select alignment polyline read-only field will change from Not Selected to Selected. Click the [Clear] button to cancel the previous selection and redo the entire process.
5. Click the [Snap] button to snap the selected roadway crossing to the alignment polyline.

Sliding Roadway Crossing Along Alignment Polyline

In cases where the snapped roadway crossing is not precisely located where it should be, the Slide Along Alignment Polyline georeferencing option allows the user to manually slide the roadway crossing along the alignment polyline. Follow the steps below to use the Slide Along Alignment Polyline georeferencing option:

1. Select the Slide Along Alignment Polyline radio button option.
2. Click the [Pick] button to select the alignment polyline from the Map View. On clicking the [Pick] button, the Georeference Roadway Crossings dialog box will temporarily disappear, and a prompt will be displayed on the status bar instructing the user to select the alignment polyline from the Map View.
3. After selecting the alignment polyline, the following informational dialog box will be displayed. Click the [Yes] button to select the polyline or abort the selection by clicking the [No] button.
4. Once the alignment polyline is selected, click the [Slide] button from the redisplayed Georeference Roadway Crossings dialog box.
5. The Georeference Roadway Crossings dialog box will temporarily disappear, and a prompt will be displayed on the status bar instructing the user to select the roadway crossing and drag it along the underlying alignment polyline.
6. Click and drag the roadway crossing on the Map View to revise its alignment.
7. When finished, press the [Enter] key or right-click and select Done from the displayed context menu. The Georeference Roadway Crossings dialog box will be redisplayed, and the roadway crossing will be georeferenced at the new location.
8. The user can also check the Recompute adjacent node element elevations checkbox option to recompute the elevation of the adjacent node type elements while georeferencing the roadway crossing.

Note: For more precision, the user can use the Snap to Alignment Polyline option first and then use the Slide Along Alignment Polyline option.

Drawing Roadway Crossing on Map View

The Draw on Map View georeferencing option allows the user to draw an alignment polyline and automatically snap the selected roadway crossing to the drawn polyline. Follow the steps below to use the Draw on Map View georeferencing option:

1. Select the Draw on Map View radio button option and click the [Draw] button.
2. The Georeference Roadway Crossings dialog box will temporarily disappear, and a prompt will be displayed on the status bar instructing the user to draw the alignment polyline on the Map View.
3. Draw the alignment polyline on the Map View. When finished, press the [Enter] key or right-click and select Done from the displayed context menu.
4. The Georeference Roadway Crossings dialog box will be redisplayed, and the roadway crossing will automatically snap to the drawn alignment polyline.

Notes:

• The user can turn on the Scale to fit checkbox option to scale the roadway crossing to fit within the alignment polyline.
• The Create curvilinear polyline checkbox option can be checked to draw curvilinear polyline segments.

Assigning Roadway Crossing Invert Elevation

The user can check the Assign Roadway Crossing Invert Elevation checkbox option to assign an invert elevation to the roadway crossing using a terrain model. Define this section before georeferencing the roadway crossing so that the invert elevation can be assigned. To assign an invert elevation, the Terrain elevation source dropdown combo box supports the following surface types:

• CAD drawing
• Elevation grids
• GIS contours
• LandXML data
• Terrain surfaces
• TIN surfaces

Depending upon the elevation data source type that is selected, different options are provided to specify additional elevation data information. The user can define an invert depth using the Roadway Crossing invert depth entry field to raise or lower the invert of the roadway crossing by the specified amount. A negative invert elevation value lowers the roadway crossing by the specified amount.