Offset alignment widening around corner - a better way?

[m_kingdon]

Hi all,

I am not sure if I am missing something, but is there a better way of adding a widening to an offset alignment around a corner?  I want to have a smooth widening by increasing the size of the radius, but instead, I get these annoying linear / curve reverse curve transitions that are not suitable for curves.

[Beka_Tchigladze]

@m_kingdon 

Widening does not work like this as Client requires, in this case you have to do it with the fillet and target it.

if you always have this type of widening you can offset and use separate alignment not offset alignment.

[m_kingdon]

This is a frequent issue I have and I think offset alignments are not fit for purpose.  I often have to model complex road designs and find myself often having to adopt non-dynamic workflows, such as separate alignments.

[Beka_Tchigladze · Accepted solution]

you need some geometry optimization it is possible to get the result even with offset alignment I have tried with this parameters and it works you can try also.

[m_kingdon]

Cheers very much for your help.  The negligible region length is a good workaround.

[Joe-Bouza]

Hi @Beka_Tchigladze 

I'm trying to get this to work. where are you setting the widening region? 

[m_kingdon]

It took me a few attempts to get it working, here is a link to a screencast.

https://autode.sk/3CnOw1b

I tried using just one curve per widening with the other curve having a length of 0.001m, but this results in strange bumps in the alignment.  Changing the curves to equal radii and the region length to 0.005 removes the bumps.

[Joe-Bouza]

I appreciate the video

questions:

why did you point out the arc length of the construction line? I never saw it referred to later.

why are transition lengths 25?  I guess I was thinking they wanted to add up to the arc length

i cant get it to work. radii keep changing , transition location keeps changing

got it close but cannot get the radii to match

[Beka_Tchigladze]

@Joe-Bouza 

Hello,

So this is very boarding really to do this type of widenings, you have to start a bit earlier till your fillet starts on transition after you have to define right transition length, you had length measured on offset alignment but you had to measured it on the alignment itself so your transition length will be 167.40' instead of 150.75',  here is screenshot and modified file.

[Joe-Bouza]

Not sure if it is worth the effort. Although, this is a standard engineering type geometry. Interesting that the software needs to be wrestled with to do it. 

[MattCichon]

Kudos to @m_kingdon for bringing up this issue and finding the solution.

Agree to @Joe-Bouza - the software should deal with it in an easier way.