Ten Easy Steps To Intersections in Autocad Civil 3D: About The Speaker
Ten Easy Steps To Intersections in Autocad Civil 3D: About The Speaker
Ten Easy Steps To Intersections in Autocad Civil 3D: About The Speaker
Civil 3D ®
Robert Gadbaw – Team Blue22 Ltd.
CV110-2L This class takes students step by step through creating an intersection using Civil 3D 2009.
Students will learn about alignments, profiles, assemblies and corridors. We'll take all of these components
and pull them together to create an intersection. Everyone will start with a surface and polylines that represent
the intersection layout.
Robert@teamblue22.com
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Ten Easy Steps to Intersections
Figure 1 shows an intersection drawn in AutoCAD® Civil 3D® using polylines in plan view.
Figure 1
Figure 2 shows how an intersection would look sketched out on paper with all baseline alignments and
regions. The sketch helps you determine where each alignment is located and where a different assembly
is required. Each different area is marked as a region.
Figure 2
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Ten Easy Steps to Intersections
Figure 3 below shows the intersection with curb return alignments and directional arrows. The arrow
directions are visible on each alignment. By having the curb return alignments going in the same direction
either clockwise, or counter clockwise, only one assembly will be required, providing the two returns are
basically the same.
Figure 3
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Ten Easy Steps to Intersections
Step-by-Step Instructions:
1. From the Alignments menu, click Create Alignment from Polyline. The Create Alignment – From
Polyline window opens.
Note: Station labeling is not required on the Curb Return alignments, but having stationing displayed
initially helps determine the direction of the alignment. Curb Return alignments typically go in the same
direction (Clockwise/Counter Clockwise).
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Ten Easy Steps to Intersections
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Ten Easy Steps to Intersections
Step-by-Step Instructions:
1. From the Corridors menu, click Subassembly Catalog.
2. Click Full Width Assembly and place it on your drawing screen by clicking on the screen.
3. To finish the command, press Enter.
4. Repeat these steps for the remaining highlighted subassemblies – Thru Intersection and Curb Return.
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Ten Easy Steps to Intersections
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Ten Easy Steps to Intersections
Step-by-Step Instructions:
1. From the Corridors menu, click Create Corridor.
2. Set the frequency and targets.
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Ten Easy Steps to Intersections
2. Click the Surfaces tab and click the Create a Surface icon .
3. Click the name of the surface and rename it to Top Surface.
4. Change the surface style if appropriate.
5. Validate that the Data Type field is populated with the Links option and that the Code field is
populated with Top.
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Ten Easy Steps to Intersections
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Ten Easy Steps to Intersections
Figure 14 shows the same profile flattened down to 2 times distortion. The car on the left is traveling
down the Main Road and the car on the right is traveling down the Side Road. The curb and sidewalk will
be removed later in the design.
Figure 14: Visualizing how the Side Road ties into the Main Road.
Step-by-Step Instructions:
1. From the Profiles menu, click Create Profile from Surface.
2. Select Side Road Alignment from the alignment list.
3. Highlight the Existing Surface and the Top Surface.
4. Click the Add button to add the Existing Surface and the Top Surface to the Profile list.
5. For the Top Surface profile, change the Style so the Top Surface and Existing Surface profiles look
different.
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Ten Easy Steps to Intersections
Figure 15: The Corridor Properties dialog box after adding the Side Road baseline and splitting Baseline
1 into 3 Regions.
Figure 16: The corridor model with the Side Road added.
Step-by-Step Instructions:
1. Right-click the corridor on screen and click Corridor Properties.
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Ten Easy Steps to Intersections
6. Click the Start Station icon to pick the start station on screen. You will want to pick the Tangent
Point of the curb return.
10. Pick the start of the first curb return, click on the end of the other curb, and press Enter.
Note: Read the command line! You will be able to tell if a new region point has been created on the
command line ONLY.
11. For Region 2 and Region 3, add .01’ to the Start Station.
12. For Region 2, change the Assembly to Thru Intersection assembly.
13. For Region 2, set the Targets again.
14. Click OK.
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Ten Easy Steps to Intersections
Figure 17: Creating a Curb Return profile and sampling only the Road Model
Figure 18 shows a curb return profile sampling only the Top Surface. When creating curb returns it is a
good idea to have a Profile View Style that shows the horizontal geometry points in the profile view. In the
example below, the horizontal geometry points are displayed in blue. The two middle blue lines represent
the start and end of the curb return. The area before the start of the curve is the Main Road sampled from
the Top Surface. And the area after the curve is the Side Road sampled from the Top Surface. The idea
here is to maintain the design before the curve and after the curve but to create a new design between
the two blue lines.
Figure 18: Curb Return profile after sampling only the Top Surface.
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Ten Easy Steps to Intersections
Figure 19 shows the same profile as in Figure 17 distorted to 2 times with the Finished Ground profile
displayed. Notice that the finished ground profile matches the Top Surface exactly in the areas before and
after the curve.
Note: The Curb Return Profile View style has horizontal geometry points turned on so the user can see
where the curb return starts and stops.
7. Click the Create Profile View to draw it on screen.
8. From the Profile menu, click Create Profile by Layout.
9. Design the Finished Ground Profile and tie it into the Top Surface.
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Ten Easy Steps to Intersections
Figure 21: Corridor Properties dialog after adding the Curb Returns as baselines.
Figure 22 below is a blow up of a curb return layout. A curb return is broken into two regions, R1 and R2.
In Baseline 3 - Region 1, the lane should stretch to the Main Road and also pick up the elevations from
the Main Road FG profile. Baseline 3 - Region 2 will stretch out to Side Road and pick up the elevations
from the Side Road FG profile.
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Ten Easy Steps to Intersections
Figure 25
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Step-by-Step Instructions:
1. Highlight the Corridor on screen and right-click. Click Corridor Properties.
8. Click to pick the stations on screen. The point to pick is the Tangent Point of the curb return.
11. Pick the intersection point of the Main Road and the Side Road.
Note: Read the command line! You will be able to tell if a new region point has been created on the
command line ONLY.
12. For Region 2, add .01’ to the start station.
13. Set the Targets for each Region.
14. Repeat these steps for the other Curb Return alignment.
15. Click OK to close the window.
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