Intersection Targets Gone Snaky

Have you ever created an intersection using Civil 3D’s magic intersection wizard?  Ok, it’s not magic, but it sure seemed that way when it was introduced.  So you’ve done one; has it ever looked totally wrong, or did something unexpected?  Read on to find out the details and the fix.

Here’s what I mean.  Notice that the lanes that are supposed to target the centrelines and ETW’s are not targeting at all.  And there is something very strange going on at the north-west corner.

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The first thing I think of is to check what’s actually being targeted.  Here is the targets dialog.

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What??!!  The lane is not even targeting anything.  The shoulder is.  Here is what my assembly looks like for the curb returns.

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Now, the key to this problem is that shoulder subassembly.  If you have a curb there you’re probably fine.  Anyway, take a look at the construction tab in the assembly properties.

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Looks normal enough doesn’t it?  Well, quite frankly, it IS perfectly normal.  However, it’s not what the intersection feature wants, nay, NEEDS.  That Lane subassembly MUST BE AT THE TOP OF THAT LIST.  The intersection feature seems to find the first thing that can accept a width target and it uses it.  I tried this with a link width and slope instead of the shoulder and it behaved badly as well.

Right click the “Left” group (in the image above…yours may have a different name) and choose Move up so that the Lane is at the top of the list. 

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All that remains is to right click the intersection in the Prospector and select “Recreate Corridor Regions”.  The targets will be reset and things should look all hunky dory now.

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Thanks for reading and hopefully this can eliminate any frustration you may have had about this.

6 comments

  1. Neil Jones says:

    That’s a useful tip – I never realised that Move Up/Move Down existed…!!!

    • Matt Kolberg says:

      It used to be that if you wanted to use a Link to Marked Point, the marked point had to be ABOVE the link in that list for it to work properly. Hence the need for the Move ability. I believe that is no longer a requirement though.

  2. MKling says:

    Jeepers! That little nugget of fun would have kept me busy for hours. Nice tip. Thanks.

  3. Lisa Pohlmeyer says:

    Awesome tip! I’ll be sure to share with my cohorts in crime!

  4. John Mayo, PE says:

    Very cool Matt. Thanks for the tip.