Creating Smart Intersections (offset alignments? intersection wizard?)

[Anonymous]

Hi Folks,

I've seen many videos and read lots of instructions that describe how to use intersections and/or offset alignments. What I have not seen or read is how to create a truly "smart" intersection. By "smart" intersection, I mean creating something that:

• Allows me to specify a radius for one offset alignment (maybe this a radius for edge of pavement)
• Takes that radius and applies it to subsequent alignments (e.g. the back of curb, edge of sidewalk and right of way are all filleted accordingly)
• These relationships remain intact when I move this intersection

The videos I've watched demonstrate how to create one filleted offset alignment, but not more than one. For this solution to be truly useful, it needs to address all of these relationships holistically.

If the answer is offset alignments, then how do I direct Civil 3D to recognize an intersection?

If the answer is intersections, how do I direct Civil 3D to use more than one filleted, offset alignment? Is the answer to use the intersection wizard and then offset the alignment it creates in order to represent the back of curb, right of way, etc.?

Screenshot attached to illustrate the challenge. Using C3D 2015. I look forward to your input!

[Neilw_05]

Simple answer, the software is not designed to work that way. The workflow is to create an edge of pavement alignment and apply a template to it for the curbs, sidewalks, etc. If you want to use alignments and profiles for all those features it's a manual process.

[Anonymous]

Neil,

Thanks. So, do you use 2D lines and curves that are manually managed to represent edge of pavement, back of curb, right of way, etc.? Or do you go about it differently?

[Neilw_05]

The intersection wizard will generate dynamic edge of pavement alignments for you. It also will generate profiles and apply the templates if you want it to. The curb return alignments and profiles are dynamic to changes in the road alignments and profiles. I recommend you spend some time learning how the wizard works.

The main caveat to the wizard is it is not well suited for intersections with non-standard geometric configurations. In those cases the process becomes manual and is a lot of work.

[Joe-Bouza]

Manually create offset alignments from those created byt the wizard - they will be dynamic to horizontal change. You need ato employ alignment masking too.

[Joe-Bouza]

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The main caveat to the wizard is it is not well suited for intersections with non-standard geometric configurations. In those cases the process becomes manual and is a lot of work.

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Hi Neil

Do you have a sample of non standard geometry? is it something like this?

[Neilw_05]

That's a good example Joe. Lots of multiple crossings by the same alignment which is not supported by the wizard.

[Joe-Bouza]

Someone should tell the wizard that because they were all done using the wizard 😮

[Neilw_05]

The complexity of the layout deceived me. After looking more closely I see there is only one case where the wizard should not work. (See attached markup of your post). As I'm sure you know, the wizard does not allow two alignments to intersect more than once (screen cap). To get around this I assume you broke your main road or side road alignment into 2 or more pieces. In this case you only have that scenario in one place so it's not a major issue. However, Imagine it occurred in multiple places along the main alignment. Your main road alignment or the side roads would then have to be broken into multiple pieces. That would not be a desirable or practical solution.

[Joe-Bouza]

I Know what you are saying but there it is. I cant find the post; I asked the very question and the poster discredited the help line and assured me that it can be done. This then prompted me to make that very file to prove to myself it can be done and as you can see it can. No tricks no work around just create intersection

[Neilw_05]

I'm dumbfounded. I just tried it and it does work. In the past I could never do this. One puzzler about this is the wizard requires offset alignments for each intersection object in order for it to create curb returns. If you create the offset alignments for the first intersection, the wizard will not recognize them for the second, so you have to create them again which you would think would result in duplicates. Yet in the end there are no duplicate offset alignments. Very strange.

I'll need to investigate this phenomenon more. If you have any links on the topic I'd appreciate them.

[Joe-Bouza]

I was too. If i come across anything Ill let you know

[Anonymous]

Neil and Joe,

Does any of that discovery change the advice I've received so far?

I pointed Autodesk help to this thread and their response was "it can't be done". That's what I'm understanding from the responses here, too. If that's the case, then all of us are manually creating and managing back of curb, sidewalk, right of way, etc., at every intersection. Sound right?

[Neilw_05 · Accepted solution]

Joe and I were discussing one of the supposed limitations of the wizard in a particular scenario. It does not apply to your original question about having the wizard create offset alignments and profiles for curbs, sidewalks etc. In most cases the wizard ca be used vs. manually creating the intersections.