& Construction

Integrated BIM tools, including Revit, AutoCAD, and Civil 3D
& Manufacturing

Professional CAD/CAM tools built on Inventor and AutoCAD
Integrated BIM tools, including Revit, AutoCAD, and Civil 3D
Professional CAD/CAM tools built on Inventor and AutoCAD
Build a cross-section of a road in Civil 3D by defining assemblies and sub-assemblies.
Type:
Tutorial
Length:
6 min.
Transcript
00:00
A cross-section of a road defines the standard design elements of roads, railways, or other linear infrastructures
00:11
at various points along its length.
00:13
In the case of a roadway, this includes road width,
00:16
lane configuration, and curbs,
00:19
as well as drainage ditches, the road base,
00:22
and other unseen structural elements.
00:26
A cross-section can help to ensure consistency in the road design
00:29
and makes it easier to visualize how the road will look and function.
00:34
To build a cross-section of a road in Civil 3D,
00:37
you must start by defining an assembly.
00:40
An assembly is a collection of subassemblies that represent the cross-sectional functions
00:45
or components of the road.
00:47
These subassemblies define the structure of the corridor model itself.
00:52
For this example, a drawing is open in Civil 3D with a
00:55
previously defined alignment and profile.
00:59
Before you begin, turn on the tool palette.
01:02
From the ribbon, Home tab, Palettes panel, click Tool Palettes.
01:08
On the palette, open the Assemblies tab, where you can access predefined assemblies
01:13
to quickly start building your corridor model based on one of the standards.
01:18
You will also need access to the Properties palette,
01:21
which you can undock for easy access.
01:24
To begin building the assembly, from the ribbon, on the Home tab,
01:29
Create Design panel, expand Assembly
01:32
and select Create Assembly.
01:35
In the Create Assembly dialog, enter a descriptive Name, such as “Two Lane with base and sidewalk” and a Description.
01:43
Expand the Assembly Type drop-down to view the available types,
01:47
and for this example, select Undivided Crowned Road.
01:52
Specify a Style, such as Basic, and then set the Code set style.
01:58
The code set defines how a surface is built from either the datum surface or the top surface that you want.
02:04
Here, select All Codes, and then click OK.
02:09
The program prompts you to specify a base location.
02:13
Once you click in the drawing the view zooms in on that assembly marker,
02:17
which represents the horizontal placement along the alignment
02:21
and the vertical placement along the profile already in the drawing.
02:25
This is simply a marker showing how the program will apply the assembly to the existing alignment
02:31
and profile.
02:33
Next, select the subassemblies to add to that assembly.
02:37
From the Assembly tab of the Tool Palettes,
02:40
select the tab for the desired item type,
02:43
such as Lanes, to review the lanes you might apply.
02:46
To review more information on each option,
02:49
right-click a lane and select Help to open the appropriate Help page with relevant details,
02:55
including the attachment point and available input parameters.
02:59
For this lane subassembly, the Help page shows multiple attached pavements and base depths
03:05
that can be applied to the base material under that lane.
03:09
You can also review the code sets.
03:11
If you know you want to build a surface for the datum elevation,
03:15
you can ensure that there is a SubBase Datum code programmed into that subassembly
03:20
to create a datum surface.
03:22
The Help page also includes a Coding Diagram that shows where each of the P codes is located on the subassembly.
03:29
Close the Help page.
03:33
Back in the Tool Palettes, select the same lane subassembly,
03:37
and notice that the Properties palette updates with the same parameters reviewed on the Help page.
03:43
Under Advanced Parameters, you can set the Lane Slope from the center line or the marker to the edge of pavement.
03:51
You can also set the lane Width and choose which Side to place the subassembly on.
03:56
To insert it on the right, set the Side to Right,
03:60
and then, in the drawing, select the marker.
04:03
The lane is automatically inserted with all of the different pavement depths shown on the Help page.
04:10
To insert another lane on the opposite side, change the Side to Left,
04:15
and then select the marker again.
04:19
You can continue building this out by adding in curbs, sidewalks, and other items that are necessary for your road.
04:28
You can also place subassemblies more precisely.
04:32
For instance, from the Curbs tab, select UrbanCurbGutterGeneral.
04:37
Then, zooming into the edge where you wish to place it,
04:40
select the circle associated with the point of intersection for that next subassembly.
04:46
Automatically, the curb populates on the right side.
04:51
You could place another curb on the left,
04:53
but before selecting a point, be sure to change the Side to Left in Properties.
04:59
If your road is symmetrical, as in this case, another useful feature is mirroring.
05:05
But first, select the left lane and press DELETE.
05:09
Then, set some daylight parameters.
05:12
From the Tool Palettes, Daylight tab, select DaylightBasin,
05:18
then zoom in and select the circle at the corner of the curb to place it.
05:24
Now, you can mirror the right subassembly.
05:27
Select the components of the subassembly, then right-click and select Mirror.
05:33
You are prompted to select the marker you want to mirror across.
05:39
Select the assembly marker, and the subassembly is mirrored to create a symmetrical road.
05:45
You can still edit the parameters of each side individually.
05:50
Select the subassembly you want to edit,
05:52
and in the Properties palette, adjust the information specific to that subassembly,
05:57
such as the Cut Slope and Fill Slope.
06:01
With the cross-section of the road created,
06:04
you can now model a corridor based on this assembly.
Video transcript
00:00
A cross-section of a road defines the standard design elements of roads, railways, or other linear infrastructures
00:11
at various points along its length.
00:13
In the case of a roadway, this includes road width,
00:16
lane configuration, and curbs,
00:19
as well as drainage ditches, the road base,
00:22
and other unseen structural elements.
00:26
A cross-section can help to ensure consistency in the road design
00:29
and makes it easier to visualize how the road will look and function.
00:34
To build a cross-section of a road in Civil 3D,
00:37
you must start by defining an assembly.
00:40
An assembly is a collection of subassemblies that represent the cross-sectional functions
00:45
or components of the road.
00:47
These subassemblies define the structure of the corridor model itself.
00:52
For this example, a drawing is open in Civil 3D with a
00:55
previously defined alignment and profile.
00:59
Before you begin, turn on the tool palette.
01:02
From the ribbon, Home tab, Palettes panel, click Tool Palettes.
01:08
On the palette, open the Assemblies tab, where you can access predefined assemblies
01:13
to quickly start building your corridor model based on one of the standards.
01:18
You will also need access to the Properties palette,
01:21
which you can undock for easy access.
01:24
To begin building the assembly, from the ribbon, on the Home tab,
01:29
Create Design panel, expand Assembly
01:32
and select Create Assembly.
01:35
In the Create Assembly dialog, enter a descriptive Name, such as “Two Lane with base and sidewalk” and a Description.
01:43
Expand the Assembly Type drop-down to view the available types,
01:47
and for this example, select Undivided Crowned Road.
01:52
Specify a Style, such as Basic, and then set the Code set style.
01:58
The code set defines how a surface is built from either the datum surface or the top surface that you want.
02:04
Here, select All Codes, and then click OK.
02:09
The program prompts you to specify a base location.
02:13
Once you click in the drawing the view zooms in on that assembly marker,
02:17
which represents the horizontal placement along the alignment
02:21
and the vertical placement along the profile already in the drawing.
02:25
This is simply a marker showing how the program will apply the assembly to the existing alignment
02:31
and profile.
02:33
Next, select the subassemblies to add to that assembly.
02:37
From the Assembly tab of the Tool Palettes,
02:40
select the tab for the desired item type,
02:43
such as Lanes, to review the lanes you might apply.
02:46
To review more information on each option,
02:49
right-click a lane and select Help to open the appropriate Help page with relevant details,
02:55
including the attachment point and available input parameters.
02:59
For this lane subassembly, the Help page shows multiple attached pavements and base depths
03:05
that can be applied to the base material under that lane.
03:09
You can also review the code sets.
03:11
If you know you want to build a surface for the datum elevation,
03:15
you can ensure that there is a SubBase Datum code programmed into that subassembly
03:20
to create a datum surface.
03:22
The Help page also includes a Coding Diagram that shows where each of the P codes is located on the subassembly.
03:29
Close the Help page.
03:33
Back in the Tool Palettes, select the same lane subassembly,
03:37
and notice that the Properties palette updates with the same parameters reviewed on the Help page.
03:43
Under Advanced Parameters, you can set the Lane Slope from the center line or the marker to the edge of pavement.
03:51
You can also set the lane Width and choose which Side to place the subassembly on.
03:56
To insert it on the right, set the Side to Right,
03:60
and then, in the drawing, select the marker.
04:03
The lane is automatically inserted with all of the different pavement depths shown on the Help page.
04:10
To insert another lane on the opposite side, change the Side to Left,
04:15
and then select the marker again.
04:19
You can continue building this out by adding in curbs, sidewalks, and other items that are necessary for your road.
04:28
You can also place subassemblies more precisely.
04:32
For instance, from the Curbs tab, select UrbanCurbGutterGeneral.
04:37
Then, zooming into the edge where you wish to place it,
04:40
select the circle associated with the point of intersection for that next subassembly.
04:46
Automatically, the curb populates on the right side.
04:51
You could place another curb on the left,
04:53
but before selecting a point, be sure to change the Side to Left in Properties.
04:59
If your road is symmetrical, as in this case, another useful feature is mirroring.
05:05
But first, select the left lane and press DELETE.
05:09
Then, set some daylight parameters.
05:12
From the Tool Palettes, Daylight tab, select DaylightBasin,
05:18
then zoom in and select the circle at the corner of the curb to place it.
05:24
Now, you can mirror the right subassembly.
05:27
Select the components of the subassembly, then right-click and select Mirror.
05:33
You are prompted to select the marker you want to mirror across.
05:39
Select the assembly marker, and the subassembly is mirrored to create a symmetrical road.
05:45
You can still edit the parameters of each side individually.
05:50
Select the subassembly you want to edit,
05:52
and in the Properties palette, adjust the information specific to that subassembly,
05:57
such as the Cut Slope and Fill Slope.
06:01
With the cross-section of the road created,
06:04
you can now model a corridor based on this assembly.
How to buy
Privacy | Do not sell or share my personal information | Cookie preferences | Report noncompliance | Terms of use | Legal | © 2025 Autodesk Inc. All rights reserved
Sign in for the best experience
Save your progress
Get access to courses
Receive personalized recommendations
May we collect and use your data?
Learn more about the Third Party Services we use and our Privacy Statement.May we collect and use your data to tailor your experience?
Explore the benefits of a customized experience by managing your privacy settings for this site or visit our Privacy Statement to learn more about your options.