Creating Centerline Alignment for Development Roadway in Civil 3D

Creating the Initial Alignment with Tangent Sections

Discover how to create precise alignments using the alignment creation toolbar in Civil 3D. This guide provides step-by-step instructions on how to navigate the toolbar, choose alignment options, and create different types of alignments such as tangent to tangent with no curves.

Key Insights

  • The alignment creation process begins by selecting the alignment creation tools button on the ribbon bar, which opens the create alignments layout window. Here you can choose your alignment name, type, starting station, and other details.
  • Options for alignment creation include tangent to tangent with no curves, tangent to tangent with curves, and various curve settings for the tangent to tangent with curves creation method. You also have the options to insert and delete 'pis' as well as convert AutoCAD lines and arcs into alignment pieces.
  • In the demonstration, a new alignment is created by selecting a start point and then choosing 'node' for each subsequent point, creating a line with no curves. The process can be cancelled at any time by hitting 'enter', and Civil 3D will automatically create the alignment based on the points selected so far.

Note: These materials offer prospective students a preview of how our classes are structured. Students enrolled in this course will receive access to the full set of materials, including video lectures, project-based assignments, and instructor feedback.

We're going to go ahead and get into the alignment creation toolbar. So what we're going to do is we're going to navigate up into the ribbon bar into our alignment drop down.

We're going to go to our alignment creation tools button and we're going to go ahead and select it. So from here we have the create alignments layout window and we again have the options for choosing our name. We're going to be dealing with our development alignments for our new development that we're working on.

So I'm going to go ahead and have a prefix of dev for any of these roadways and this is going to be our main road that's going to connect to our highway. So I'm going to go ahead and call this dev main. So from here we have the options for what is our type of alignment.

I'm going to go ahead and choose centerline because I know that I'm going to be creating a centerline alignment for this type of alignment. I am going to go ahead and leave my starting station as zero. I'm not going to put in a description.

I'm going to go to my drop downs here. I'm not going to choose a site. I am going to go ahead and leave it as proposed for my alignment style.

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My layer is going to be c road and I am going to go ahead and have all labels for my alignment label set. So from here I'm going to go ahead and click okay and when I do that Civil 3D opens up my alignment layout tools window. So from here you have your options for how to create alignments.

You have options for creating alignments tangent to tangent with no curves, tangent to tangent with curves, and then the curve settings for your tangent to tangent with curves creation method. Then we have the options for our pis. So inserting pis, deleting pis, and breaking our pis.

Then we have the options for creating individual lines, individual curves. We have options for spirals. We have options further options for spirals.

Now in this class we're not going to deal with spirals. Spirals are a very specific type of curve that you use. You spiral into a curve, you spiral out of a curve.

I don't use them in my day-to-day workflows so we're not going to be covering them in this class but these are available to you in these three options. So moving on from there we have the options for converting AutoCAD lines and arcs into alignment pieces. Then we have the option for changing the direction, so reversing the sub-entity direction.

We have delete sub-entities and then we have the options of viewing and editing our alignments that have been created in different methods. So from here we're going to go ahead and drop down and select our tangent to tangent with no curves first. So from here Civil 3D is going to ask me to specify a start point.

So what we're going to be doing is we're going to be using these red points inside of our drawing to create an alignment. Our first alignment is going to tie into the highway. It's going to come down and through and down to this blue cul-de-sac point.

So the second alignment we create will then branch off of our main alignment and come down and around this direction. So what we're going to go ahead and do is we're going to shift right click. We're going to select node and then from there we're going to zoom in to this first point and I'm going to go ahead and select node.

Then I'm going to zoom back out. I'm going to skip over this point because this is the beginning point for my branch alignment. I'm going to go ahead and shift right click.

I'm going to choose node again. I'm going to lock into this point here and click on the node. I'm going to continue through, shift right click, select node, pick this point and then I'm going to go down to this point here, shift right click, node, pick this point.

I'm now going to hit ENTER to cancel my command and Civil 3D automatically creates our first alignment based on tangent to tangent with no curves. So you can see here we have a line that has no curves associated with it. It's just tangent sections and so we're going to go ahead and save our drawing and then we're going to meet in the next video where we're going to add some curves to this alignment.

photo of Michael Kinnear

Michael Kinnear

Civil 3D Instructor

Mike is a Civil Engineer and a member of the American Society of Civil Engineers. He brings a wealth of experience working on transportation engineering and site development projects that involve working with Civil 3D, AutoCAD, and MicroStation. Mike is an avid hiker and enjoys spending time with his family in the local Cuyamaca and Laguna mountains.

  • Autodesk Certified Instructor (ACI)
  • Autodesk Certified AutoCAD Civil 3D Professional
  • Civil 3D
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