Editing Superelevation Locally

Once the superelevation values are defined and the 3D Alignment is generated, you can locally overload the superelevation rate (maximum value: eMax) on key points/alignment points (maximum slope on the road turns) or edit the laws representing the angular variation on curves. You modify what has been previously set in Automatic mode: the superelevation values are not chosen from the tables, but from the overloaded alignment points.

Overloading gives the minimum value of the maximum superelevation. If the tables contain a higher value, this value will be taken into account.

Profiles, traveled way/shoulder lanes distribution and vehicles types are stored and managed in an xml file in Data Setup, called in the RoadAlignmentDesign.xml for road design. For more information, see Alignment Design Customization.

  1. To change the superelevation value, double-click an horizontal alignment in the tree.
    You switch into the Alignment Sketcher app. The Alignment assistant panel appears.
  2. Double-click a key point.
    The Alignment point dialog box appears. It is split into two sections:
    • Parameters: used to create the horizontal alignment. For more information, see Creating a Horizontal Alignment.
    • Design Rules: predefined status have already been defined (for radius, length, gradient and superelevation) in design rules which are a series of recommended parameters to check the correctness of transition formulas.
    Note: Road specifications, traveled way lane/shoulder lane distribution can also be modified from a given station using the Alignment point dialog box.
  3. To edit the superelevation rate, do either of the following:
    • Under the Parameters section, use the combo box of Superelevation to edit the rate of the maximum slope in the following road turns (5% for example). The slope angle on the selected alignment point is not modified, next alignment points inherit from the current rate and the Superelevation field is renamed into Current superelevation containing the inherited rate.

      To modify the superelevation value again, click Edit next to Current Superelevation.

    • Under the Design Rules section, use the combo boxes to edit the superelevation tables/laws (defined in Design Rules in Data Setup) used to connect transition sections with different superelevation rates. For more information about design rules/tables, see Building and Civil Resources in the Data Setup User's Guide.

      When no superelevation value has been set, the current value displays the information of the previous alignment points.

      Design Rules can be selected in session. They allow to define several horizontal radius tables depending on a superelevation rate. For example, you can add curve radius rules according to the speed.

  4. To edit the design rules/tables, use the combo box of:
    • Radius table: the higher the speed is, the higher the radius must be to counteract the centrifugal force and therefore prevent the vehicle from overturning or skidding.
    • Length table: the aim is to have minimal lengths.
    • Gradient Table: gradient corresponds to longitudinal slopes. They are chosen according to the speed for example.
    • Superelevation table: superelevation corresponds to transversal/cross slope.
  5. Click OK.
    An alignment sketch is created, connecting transition sections (superelevation) between key points. Key points contain speed and superelevation information for design rules.
  6. To return to the Civil Engineering 3D Design app, click in the Alignment assistant panel.