Tech Tips

Creating a Road Intersection

This Tech Tip explains how to add or create an intersection using the new roads strings model.


In Civil Designer 2014, there are 2 methods used internally for road design. The old method of using cross sections, and new method strings. The design method can be changed at anytime and any older project done in any previous version of Civil Designer can be converted to a string version of the road design. Junctions will only work if your road is using the strings method. The steps you follow for your road design are identical to all previous versions.

Add a Junction (intersection)

Roads Mode > Junctions Menu > Add Intersection

The program will prompt

With the mouse indicate the Intersecting Road of the junction.

The intersecting road will be highlighted

Then select the Main Road of the junction.

If the roads have not been converted to strings, or you did not start your roads as a strings road ( i.e. you started the project in an older version of Civil Designer), the following dialog will appear. In this example the roads are not string roads.

The roads will have to be converted if you wan to add a junction, so you will select Yes.

Intersection Design

The next step is to specify the various settings for the new intersection.

You can also change the intersecting and main roads if they were selected in error. You can reselect by using the mouse or selecting from the drop down.

You can also change the settings for the left, right curves even specify a center island if necessary. All these dialogs have extensive help, press F1 with the dialog open to get additional information.

If you have intersections with the same settings in your project, you can also save the intersection details and then use them again, or create intersection libraries.

This is done via the Load, Save and Save As buttons

Once you are happy with all your settings, click OK.

The new intersection will be added to your project.

We used the incorrect settings for the curves, so now we can edit the junction and correct this.

Editing the Intersection

Roads Mode > Junctions Menu > Edit Junction

Click on the junction, the Intersection Design dialog will appear.

We will select Left Curve

We will change the radius.

We will do the same for the Right Curve.

Once the changes are made, click OK.

The intersection will be recalculated and the intersection will be updated to reflect the changes.

The updated intersection.

Deleting the Intersection

You can also delete the intersection, if no longer required.

Roads Mode > Junctions Menu > Delete Junction

Indicate the junction, and the junction will be deleted.

Click Yes to delete the junction.

The original string roads without the intersection.

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