AutoCAD Civil 3D

[#1]

Hi All,

I have two assemblies that represent road cross section at two points along a corridor. I want the corridor to transition smoothly between the two cross section so that if I look at a section halfway between the two assemblies it will have an intermediate width. Doing this with a simple transition assembly doesn't seem to be the most efficient approach since my offset or target actually changes as one moves up the corridor. Has anyone figured out a way to accomplish something similar? Is there a way to generate a polyline or some other type of entity that could be used as a target?

Cheers!

[#2]

Yes, using the ConditionalHorizontalTarget subassembly.

[#3]

Hi Fred,

Could you please elaborate on how that subassembly actually works given my scenario. I've used it before when I want my corridor to search for various targets but ca't figure out how I can get the transitioning width behaviour. Seems like my problem could be solved if I could just figure out a way to create a polyline whose offset distance varies along its length.

Thanks for your time,

Aaron

[#4]

I was just answering your last question there..

Sounds like a normal horizontal transitioning scenario. What's going on?

Throw us a bone...provide a picture.

[#5]

Hello Aaron,

First off - welcome to the board.

I'm not entirely sure that I understand what you're trying to do here.  Are you familiar with offset alignments?  Based on your description it sounds like that would be the solution for you.

[#6]

Thanks for the welcoming spirit. Yeah I am totally familiar with offset alignments and using alignments, featurelines, and profiles for targets in corridors. I found a work around that is decent but not as elegant as I had hoped for. The attached image shows the results of my efforts. I created a tapered polyline offset and used those offsets as target alignments to vary the width of a channel along a corridor. I was hoping to have something that is more dynamic....i.e. if I were to change my alignment geometry the variable width (target offsets) would adjust automatically rather than having to manually create the tapered polylines each time my aligment changes.

Let me know if there is a more elegant way of doing this.

Cheers,

Aaron

[#7]

Can you not use offset alignments with widenings applied to them?

[#8]

Thanks for the great help folks,

I'm a little confused on how I would specify a varying width offset. The create widening specifies a lateral widening that would work for a bus stop or widening that then would transition back to the regular offset. My previously posted image sort of show what I'm trying to do via the brute force method. I gues the real question is, can I create an offset alignment whose offset varies as a function of the station value. For instance, if I want a 20 foot offset at station 0+00 and a smooth transition to an offset of 10 feet at station 10+00. The offset alignment wouldn't be a true parallel offset but would neck down or taper as a function of station value.

Cheers,

Aaron

[#9 · Accepted solution]

Here's a drawing with two offset alignments.  I've adjusted the stationing of the widenings so that essentially the entire length of the offset alignment is a taper.  You can edit the centerline and the offsets will adjust so suit.

[#10]

Steve's drawing should give you the idea. You may have to finagle the start and end regions a bit to get the taper to be fully within the range of your centerline.