Overrides: Controlling a Guardrail
Updated August 06, 2021
This article applies to:
- RoadEng Civil
- RoadEng Forestry
This example illustrates how to control the position of a guardrail by overriding the template offset distance.
To follow this tutorial, download the corresponding files here: guardrails.zip
This example uses the Guardrail template component. The operation and behavior of this component is briefly explained. The logic and procedures used to create this component are not covered.
The example consists of a short section of existing road approaching a bridge. The first step is to add a guardrail to our template and then assign it to the bridge approach. The second step is to adjust the offset to taper the guardrail into the bridge.
Creating a Guardrail Template
1. Open the Location module. Select File | Open GuardRail.dsnx (included with this example). The screen should now display a cross section window and a plan window as shown in Figure 1.
Figure 1: Cross Section and Plan Views
2. Choose menu Home | Templates. The Template Editor shown in Figure 2 is displayed.
Figure 2: Template Editor
The Rural Paved template is selected because it is assigned to the current section. A copy of this template will be made then a Guardrail will be added.
3. With the Rural Paved template selected, right click and choose menu Copy.
Figure 3: Create a Copy
4. Again, with the Rural Paved template selected, right click and then choose menu Paste | As New.
A new template will be created at the bottom of the template editor with id set to XXX.
5. Click on the new XXX – Rural Paved template and press the Properties button. Change the description to “Rural Paved w. Guard Rail” and press OK. Note XXX can be renamed if desired.
6. Open the Walls and Barriers Component Folder by clicking on the “+” button to the left of it (or by double clicking on the folder icon). Select Guardrail component, right click and choose menu Copy.
7. Expand the new XXX – Rural Paved template by double clicking on it. Right click and choose Paste | As New - Left.
Fugure 4: Paste Component
At this point a new Guardrail component has been added to the XXX – Rural Paved w. Guardrail template on the left side. Copy/paste will now be used to duplicate this component onto the right side.
8. Right click again and choose Paste | As New - Right.
Figure 5: XXX Rural Paved w. Guard Rail Template
A basic guard rail template has now been created. Before the road alignment is recalculated, you need to assign the new guard rail template using the Assign by Range option. The Guardrail template will be assigned from station 36+00.0 to 36+99.5.
9. Choose menu Home | Assign by Range and then choose the Templates tab.
10. Under template name select “XXX – Rural Paved w. Guard Rail”. Set the Station range 3600, 3699.5. Press the “Add/Edit” button. Notice the assigned ranges list changes. Press OK and this time respond OK to “Recalculate Range”.
Fugure 6: Assign Template by Station Range
Displaying the guardrail in the Plan window
To display the guardrail in the Plan window, select and draw one of the guard rail point codes. In this example, point code “GP6“(which is the top inside point nearest c/l) will be displayed.
11. Right click on Plan View | Plan Options. Enable the Template Options checkbox and click on the “+” button to the left. Press the Add button and choose “GP6L” (Left) and press Add. Choose a distinct line type to display the guardrail in the plan window as shown below.
Figure 7: Add Template Codes
12. Repeat step 10 for “GP6R” (right side).
13. Press OK to return from the Template Editor and OK to the “Recalculate Range” prompt.
14. Scroll up in the Plan Window until station 36+00 is visible. Notice the guard rails are displayed (see Figure below).
Figure 8: Rails Displayed in Plan View
Overriding Template Parameters to Control the Guard Rail Offset
The plan position of the guard rail will be adjusted by overriding a parameter. The parameter POST_OFFSET is the distance from C/L to the inside of the guardrail.
15. Choose Home | Assign by Range and then choose the Overrides tab. Find and select Post Offset (Left Side) in the list of parameters.
16. Using the Add button set the following values (De-select “Use Default” to enter a value).
Adding a Description is optional.
Figure 9: POST_OFFSET Overrides
17. Repeat step 16 and 117 for POST_OFFSET (Right side). Press OK and respond OK to “Recalculate Range”. The profile window should appear as shown in the figure below.
Figure 10: Guard Rail