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Road Intersection

Use this dialog to create new or edit existing intersection objects.

The construction is performed in the integrated program Kryss3D, which is specifically developed for designing road intersections in 3D. Kryss3D does not design the centerlines; these must be fully designed in Gemini Terrain before the intersection can be calculated. The result of the intersection calculation is written to a VOB file, which Gemini Terrain uses for further handling of the intersection.

Where can I find the dialog?

In the terrain model drawing toolbox, select the Road Intersection icon and the Road Intersection tab.

Creating a New Intersection

Procedure

  1. Select the Intersection icon in the toolbox.
  2. Click Add… and point to the first road to include in the intersection.
  3. Click Add… and point to the second road to include in the intersection.
  4. Optionally, add more roads if the intersection has more than three arms.
  5. Click New Intersection... to start Kryss3D.

Special Cases

Loop Intersection

In this case, you have only one designed road. To design an intersection, you must have at least two roads. The solution is to split the road into two.

Procedure

  1. Click Add… and point to the road to include in the intersection.
  2. Select the road in the list, click Split…, and point somewhere on the loop.
  3. Click New Intersection... to start Kryss3D.

Example of a loop intersection

Intersection Where One Road Has a Loop

Here, you must split the centerline with a loop and delete the part not included in the intersection.

Procedure

  1. Click Add… and point to the first road to include in the intersection.
  2. Click Add… and point to the second road to include in the intersection.
  3. Select the road with the loop, click Split…, and point somewhere on the loop.
  4. Select the road not included in the intersection and click Delete.
  5. Click New Intersection... to start Kryss3D.

Composite Intersection

When two intersection solutions are so close that they cannot be separated into two intersection objects, this is solved with composite intersections. A typical example is a Z-intersection, which is actually an X-intersection with two nodes. If the distance between the nodes is less than 60 meters, you can only create a composite intersection.

Example of a composite intersection (Z-intersection)

Edge Lines in the Intersection

The edge lines in the intersection inherit the cut/fill parameters from the designed roads. If you want to override these in the intersection area, you must select Manual in the method column. The functions are found on the right mouse button.

Editing the Intersection When Reference Lines Change

  1. Changes in the standard profile reset the project.
  2. Changes in design parameters reset the project.
  3. Changes in the superelevation diagram update elevation data. The project continues.
  4. Changes in the width extension diagram update road lines. The project continues.
  5. Changes in the vertical data of reference lines update elevation data. The project continues.
  6. Changes in the horizontal data of reference lines may cause the project to continue or reset.
  7. Changes in the number of reference lines reset the project.

Other Options in the Dialog

Calculation Standard

Select which calculation standard to use. The program includes predefined material types for NS3420.

3D or 2D Calculation

Full 3D calculation requires that the roads included in the intersection are fully designed. 2D calculation allows you to construct an intersection without the centerlines having vertical curvature.

Annotation

You select which lines receive annotation under the advanced options tab. The points are written to the material report file and also saved in the intersection project for later drawing.

For inner/outer central islands in roundabouts, the program annotates points in 16 sectors. For other lines, the program annotates curve points. Note that it is not possible to move annotations manually in the plan view.

Example of intersection annotation

Application Layer Presentation

With this option, you can draw the intersection through an application layer. The advantage is that you have access to all presentation rules available here.

Procedure

  1. Create an application layer using the ModellPresentasjon.al_ template.
  2. Open the properties dialog for the excavation pit.
  3. Check Presentation and click the ... button.
  4. Select the application layer you created and click Open.
  5. Click OK in the dialog (you can also turn the presentation on/off in the application layer list).

The ModellPresentasjon.al_ template is a starting point for adjustments that you can save as your own templates.

You can read more about how to draw models through application layers in the user documentation: Drawing models through application layers.

Draw Materials

Check if you want to visualize the materials in plan and 3D. Which materials are displayed depends on the choices in the Material Result tab.

Build Layers / Calculate Materials

Check if you want to rebuild the layers when you exit the excavation pit dialog. If you make changes to the intersection that affect layer construction, this option is automatically checked.

Save Data

You work with a data structure in memory (not directly with the storage format). Only when you use the general save options in the File menu, toolbar, or the Save Changes... button in this dialog, is the content written to file.

If you undo changes, you can click Ignore Changes.... The content from the previous save is then retrieved.

With the Save Copy As... option, you can create a copy of the EFI file.

Known Limitations

In roads with a median, problems may occur with the transition between road and intersection. This is especially true where the median changes the road's slope or when the carriageways have different heights near the centerline.