AutoCAD Civil 3D

[#1]

I am using corridors to model a driving course. I have attached two images that show 2 scenarios. One is where an alignment loops back onto itself. The other is similar to a merging lane.

What are the best ways to handle these? I am having a hard time with the surfaces overlapping. I have tried using targets, but they don't work well.

[#2]

First thing that comes to my mind is Intersection. I'm not proficient enough to help. Old school intersection can do this too, but in both cases you may want to break the alignment, looping alingments can be a problem.

[#3]

Looks simple enough.  Split the loop into two alignments and corridors so that you can target from each one to the other.  You will need a full width assembly and a half road - right side assembly.  What do you plan to do for the lane crossfall in the merge area?

For the exit ramp its' pretty much the same thing.  One full width assembly for most of the roadway and two half sections for the areas where the roadway splits.

[#4]

Why the two half widths? Do I use the right side section for road A and the left side for road B?

[#5]

Yes - the yellow piece will be built from the left section and the red piece from the right half section.  The tricky bit is the section between them where the right lane of one road is crossing the left lane of the other one.  You need to think about how you intend to handle the crossfalls in this area before you can determine how to build the assembly and corridor for this piece.

[#6]

Also,  I assume this does not need to be an intersection, but rather just targeting an outside alignment of each corridor?

Thanks for the help.

[#7]

I would use the intersection wizard to start - it helps with locking the profiles together and adding the offset alignments you will need.  You can skip the steps for building the offset profiles and the corridor, then work through the rest of it on your own.

If you can post a drawing with the alignments, profiles and basic template information then I'll try to find some time to build an example for you.