Superelevation General Workflow
The general workflow for superelevation is described in the following steps. Steps 4-6 can be done in a different order and not all steps are required.
Review and edit as needed.
Create the Super Section(s)
In this first step, the Civil horizontal geometry element is identified, and station limits of the superelevation are defined. Station limits are useful if the horizontal geometry element is substantially longer than the project limits.
In a basic project where the through lane pavement configuration is consistent (i.e., all 2 lane rural with a few turn lanes), a single section may be used. However, if there are significant changes to the road, i.e., changing from 2 lane rural to 4 lane divided, separate sections should be created.
The general rule is create a new section if you are using rule-based calculations and the through lane configuration or pivot method changes. The changes should be based on the through lanes, as auxiliary lanes such as turn lanes, ramp entrances and exits and truck climbing lanes are handled independently. If you are importing superelevation, one section can be used for an entire alignment.
Alternatively, a corridor can be selected instead of an alignment. When a corridor is selected, you are prompted for the superelevation xml file, and the program will create the sections along the corridor's alignment, automatically create the lanes (step 2) based on the corridor cross-section(s), calculate superelevation (step 3), and assign the superelevation to the corridor (step 6), all in one step. Note: for the superelevation to be assigned to the corridor (step 6) the corridor must exist in the active dgn file.
See also Create Superelevation Sections
Define the Lanes
Once the section is defined, define the lanes. Focus on the through lanes, as the turn lanes and intermittent lanes can be added at any time. Lanes are defined by selection of the horizontal geometry and offsets. Default cross slope, used for subsequent calculations, is also defined. The result of this step is that graphic lanes (filled with green and yellow, no choice of colors) are drawn.
See also Create Superelevation Lanes
Calculate Superelevation Transitions and Cross Slopes
In this step, transition lengths and cross slopes are calculated using the parameters in the Superelevation Rate file and stored as part of the superelevation lane graphics. It is easy to see the results if the fill is toggled on as the lanes change from solid yellow and green to a gradient coloring, based on cross slopes. When a lane is selected, the station and cross slope are displayed as editable text.
Alternatively, the cross slopes can be imported as comma separate values (CSV) from a text file containing the station and cross slopes, which were calculated by an exterior program (or manually).
See also Calculate Superelevation
Review and Edit as Needed
There are several ways to review the superelevation data and edit if desired. Highlighting a section displays station and cross slope values for review and editing. Stationing can be changed dynamically by selecting the gray wedge and dragging to the desired station. Each lane can be manipulated independently of the adjacent lanes. The station can all be keyed in by selecting the station text.
The superelevation editorcan be used to edit the data, in a tabular format. Any changes made in the editor are automatically synced with the graphic lanes and vice versa. The fields in the editor can be customized so unused or unwanted fields can be hidden. Any data in gray cannot be edited, due to constraints used during calculations.
A Superelevation View which shows a dynamic superelevation diagram can also be used to edit the definitions.
Add Auxiliary Lanes
At any time during the process, additional lanes can be added in any section. Primary lanes (those lanes that are rule based) or auxiliary lanes (those with user-specified cross slopes) can be added. The result of this step is graphic superelevation lanes.
Associate to a Corridor
At any time during the process, the superelevated lanes can be associated with a corridor. If the superelevated lanes are in a different file than the corridor, you must be in the corridor file with the superelevaton lanes attached as a reference. They can both be in the same file.
The result of this step is the superelevated pavement is reflected in the corridor model.
See also Assign Superelevation to Corridor