A New Aid in Intersection Design

Wow, it’s been a while, hasn’t it?   I’ve got a ton of ideas floating around for posts, now I have to make the time to get them down into text form.   

Everyone knows my feelings about intersection design in Civil 3D – there have been many discussions about how I feel regarding intersections.   As I force myself to become more and more proficient with intersections, I have grown to almost enjoy them.   However, some people just don’t understand the concept – they can get regions outside the intersection pretty easily, but the whole “create more alignments and profiles” makes the process pretty tedious, especially when those other alignments and profiles have to match other alignments and profiles EXACTLY.    Just yesterday I saw a residential subdivision that had a really nice road network designed, but all intersections were empty – grading those by hand negates the whole dynamic model, doesn’t it?   

A few months ago, I discovered a great tool that cuts my intersection design time down greatly.   It’s no magic charm, but it does take a time-consuming task and make it much more bearable.   Follow the link to find out what this tool is and how to get it.

Intersection Builder is a tool developed by Jon Rizzo of Langan Engineering and Environmental Services.  As I stated above, the tool is not a magical solution that reaches deep into your head and designs your roads for you, but it eases the headache caused by having to create so many alignments and profiles to define corridor targets.   As long as you have alignments and profiles created for the main alignments (the centerlines in many cases), Intersection Builder will take care of creating the curb rounding alignments and profiles for you.    Since these profiles have to match exactly at both ends, this is often the most time-consuming part of the design process.   OK, let’s be honest – I find it completely mind-numbing.    Let’s see how it works…you can see in the image below that I have the basic starting points for creating a roadway – I have two intersecting baselines with associated profiles, both existing grade and finished grade design profiles.   We’ll use this information to model our curb returns.

Alignments and profiles

Once I decide that it’s time to model my intersection, I simply click on the Intersection Builder icon that is on the toolbar that comes with the program.

Intersection Builder Toolbar

This brings up the following dialog box:

Intersection Builder Dialog

As you can see in the above image, this is THE dialog box that allows you to create your curb rounding alignments and profiles.    You specify your Primary and Secondary roadway on the top, and the profile to be used (FG, of course.)   You can put the new profiles and alignments on a site or let them be siteless.   If you want to use the same design values for all curb roundings, you can set those values in the upper right corner.    Things can be picked graphically or manually entered in the box.   You specify your curb rounding radius, typical pavement width, or elevation, click OK, and the alignments and profiles are created, as shown below:


The profiles will show up in prospector, but to display them, you have to go to Profiles>Create Profile View and create a view for the new profiles.


Once the profile views are created, they can be modified as any profile can.

From what I’ve seen, the price is right on this software – only $150 per seat as reflected on the Langan  website.   As I stated above, it’s still no magic charm – you still have to create CL profiles and alignments, and link those together as you always have.    However, for what it DOES do – helps me to create intersections faster than I could before, it’s worth at least double the price.


  1. Kevin Spear says:

    This is definitely a slick way to handle int – design. Although, I gotta bust you a little bit for calling it new. I think Jon had this back in the 2006, maybe 2005 version. 🙂

    I’m sure it has changed sine then. He asked me to give him feedback, but honestly, it does exactly what they intended it to do. The next step would be somthing like Cadapps has….

    Anyway, my 0.02.

  2. Jason Hickey says:

    OK, would you be happy with “New to me???”

    Yeah, he was busting my chops today too – so I’m a latecomer to the game… 😉

  3. Nick Zeeben says:


    You really need to cut the guy some slack. I mean he did just get highspeed internet. Thats only like 6 or 8 years after the rest of us. In this case he is only like a couple of releases behind.

  4. Kevin Spear says:

    Cut Jason slack? Sure… 🙂 Just a little friendly banter, eh?

  5. James Bell says:

    So does the alignments and profiles that this creates update automatically whenever you change your main alignment or profile?

  6. Nick Zeeben says:

    The alignments and profiles are regular Civil 3D objects, they dont update when the road CL’s change.