2.0

Modifying Design Control
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grade of the superelevation region which, in turn, can be changed. The template
may have been drawn with the grade at 2.0%. You can use this method to
change the grade to 1.5%.
To edit the template superelevation parameters using the Edit Design Control
command
1 Use the Pivot list to set the pivot point.
You can set the pivot point to the left or right edge of the superelevation zone,
or you can set it to the centerline.
2 Set the grades of the template superelevation zones in the Left, Center, and
Right boxes.
Enter these grades as decimal values rather than percentages. The values display
as ft/ft (e.g. 0.02 = 2%). A zero value in either the left, center, or right
superelevation zones indicates the place where the template is held (hinge
point).
The values for cross grades calculated by the Slope Control dialog box are
displayed. The raw condition is used in the cross grades calculations.
3 Select the Rollover check box, and then enter the rollover value in the edit box.
The rollover rate is the maximum allowable grade change between the
superelevation region and the rollover region. Enter the percentage as a decimal
value in the center edit box, such as .06 for 6 percent. The Superelevation
Rollover scroll box indicates the side of the template that shoulder rollover is
applied to.
4 From the Subgrade Superelevation Method list, you can select the following
types of superelevation that are applied to the subgrade surface of the template:
n
None: The subgrade surface is not superelevated, and maintains its location.
n
Parallel: The subgrade surface superelevates parallel with the normal surface
of the template for the entire width of the subgrade.
n
Fixed Break: Using this option, the subgrade below the template
superelevation region superelevates, and the subgrade outside of the
superelevation region wont. When you define a template, you can use the
subgrade break point offset modifier option to set the location of this break
point in relation to the outer superelevation point. If the default of 0.00 is
used, then the break point occurs directly below the outer superelevation
point. If a positive value is entered then the break point is shifted by that
amount toward the centerline and a negative value shifts it away from
centerline.
NOTE
Because the subgrade surface is often at a steeper grade than the normal
surface, enter values for the Transition In and the Transition Out under in
the Superelevation Curve Settings dialog box. These distances control what
distance it takes for the subgrade surface to adjust to a grade where it is
parallel with the normal surface.