In this exercise, you will edit the profiles that define the vertical geometry of an intersection object. You will edit the profiles graphically and parametrically, and examine how the changes affect the intersection.
Examine locked PVIs
This drawing contains an intersection of a primary road (Road A) and a secondary road (Road C).
Notice that lock icons are displayed on three of the PVIs. The lock icons indicate that the PVIs are locked to another profile. When the intersection was created, the middle PVI was created at the point where the secondary road intersects with the primary road profile. The other two PVIs were created to maintain the primary road crown through the intersection, and are locked to the edges of the primary road.
In the Profile Entities vista, notice that a is displayed in the Lock column for PVIs 5 through 7.
Information about the locked PVI, including alignment, profile, and intersection, is displayed in a tooltip. PVIs that are created as part of the intersection creation process are dynamically linked to the primary road profile.
You can unlock a PVI by clicking the icon. If a PVI is unlocked, the profile will no longer react to changes in either the intersection or primary road profile.
The PVI is locked at the current station and elevation. Notice that another icon is displayed on the profile, and the PVI Station and PVI Elevation values are no longer available. A PVI can be manually locked to a specified station and elevation value. Manually locked PVIs are not affected by modifications to other portions of the profile.
On the ribbon, the Intersection tab is displayed. Tools for adjusting the side road profile are displayed on the Modify panel. You can edit the primary road profile with the standard profile editing tools.
Modify the secondary road grade
The Secondary Road Profile Rules dialog box is displayed. Use this dialog box to specify the secondary road grade entering and exiting the intersection.
Enter the parameters in the following order.
This option enables you to specify a distance from the intersection of the primary and secondary road alignments. This enables you to extend the side road grade rules outside the extents of the intersection.
In the lower right viewport, a new PVI is created 100 meters to the left of the locked PVIs. The grade entering the intersection is 0.21%, which is exactly 2.00% less than the primary road grade.
You can move the grip at the PVI to make minor changes to the profile. If you drag the grip outside the range of parameters specified in the profile grade rules, the grip snaps back to the default position that satisfies the grade rules.
Add a low point to a curb return profile
The grips indicate the extents of the curb return profile. The profile portions that are outside the extents represent the offset profiles. Changes to the offset profiles affect the curb return profiles, but changes to the curb return profile do not affect the offset profiles. Use the grips to extend the curb return profile along either offset profile.
A low point facilitates drainage along a curb return. In the following procedures, you will see how the curb return reacts to changes in other objects.
Move the primary road alignment
In the bottom right viewport, notice that the three dynamically locked PVIs moved to a new location. This happened because you moved the alignment to which they are locked.
In the top right viewport, examine how the changes to the intersection location affect the curb return profile that you modified.
Change the primary road profile elevation
In the bottom viewport, notice that the three locked PVIs moved up to accommodate the new primary road elevation.
In the top right viewport, the PVI you added to the southeast curb return has stayed in the location you specified, but the ends of the profile moved up to accommodate the new elevation of the offset profiles. The ends of the curb return profile are locked to the offset profiles. You must manually update PVIs that have been placed within the profile.
To continue this tutorial, go to Exercise 3: Creating and Editing a Corridor in the Intersection Area.