The boundaries are available through the Road Surfaces dialog, located at the top of the list of surfaces for the left and right sides, respectively.

Boundaries are used to limit the extent of the road model data in the cross-sections. Typical use cases limit the road design against other road models, buildings, structures, or design data. The boundaries will clip all road model data at the defined left and right limitations of the model. It is also possible to define that the limitation is because of a bridge/tunnel which will remove the fill/cut solids within the sections.


Define a from-to interval for the boundary. When using different limitation elements the boundary description can be divided into subsections.

Subsections need to be defined based on at least two station values (start-end stations). Within the start-end sections, there can be multiple intermediate sections if needed.

Subsections can be split with a Break. Add a break by writing any text in the chainage column.

Methods of Defining Boundaries


Select a surface from the pull-down menu of the column Surface and define the end station of the boundary in the next row.


Click the button New Line in the lower right corner of the dialog box.


This method is an extension of the two methods above.


The object column makes it possible to define that the boundary used is related to a location of a bridge, tunnel, or retaining wall.

In addition to adding left/right limitations to the model, when using Bridge or Tunnel the road calculation will cut away the features for Cut and FillLayers that are in between the left/right boundary. This means that the solids and volumes will not be part of the resulting model. This will improve the Quantity reports and how a model is presented in a view (typically in an interchange with road models crossing each other with different elevations.

How to use

Note: The road pavements will not be affected and thicknesses for the pavement needs to be adjusted in the Pavement dialogs.

Figure 1: Add bridge or tunnel in the Object column.

Figure 2: Visualization of how the boundary related to a bridge works. 

Tip: Using a Retaining Wall object will not give the same functionality as Bridge/Tunnel, and is just informational in the dialog.

Next topic: Ditch Design