The 12d Model Intermediate Civil Design training will equip you with the powerful techniques to create Super Alignments as Control Strings.

Intermediate Civil Design

This course is in-depth training in the creation of Super Alignments as Control Strings (Road Centrelines).  ‘Super Alignments’, can be created using Intersection Points (I.P.s) or Parametric Elements.  Usually referred to as ‘SA’s, the Super Alignments are intelligent objects that can reference each other so that when one changes, the other follows.

The course explores the concepts of Parametric Design, where elements are either Fixed, Floating, or Free, before moving on to defining ‘Computators’, which link the SAs together, and Chains which allow linked SAs to be updated in one operation.

Prerequisites: ‘Getting started  Design’ or good working knowledge in IP-based SA design.

At the end of the course participants will have an understanding of the ideas behind Parametric Design, and will have learned the techniques for creating and edited Super Alignments both using I.P.s and using Fixed and Floating elements (Parametric Design).

Participants will gain an understanding of the ideas behind parametric design elements, and develop a good working knowledge of the use of these elements in the design of control strings.  They will be familiar with the techniques for ‘Computating’ Super Alignments where one SA strings references another for it’s position.

Course Summary


  • The course starts with an exercise in road design using parametric elements, running through methods of creating straights and arcs without I.P.s.
  • Various types of geometry are calculated, including compound curves, back to back curves (with no tangent), and traditional curve – straight – curve design.  We look at different ways to defining curves – through two points and tangential to a straight, through two points and a radius, and as a fillet.
  • Once the exercise is complete we discuss the three different types of parametric element, and how they can be used together.
  • To reinforce the techniques described, we go on to use the parametric elements to complete the horizontal design for part of a land development project.
  • When horizontal design is complete we create the vertical design, using I.P. methods for some alignments and Parametric Elements for others.
  • Super Alignments can be assigned a ‘style’ to display chainages, symbols at TPs and the like.  We investigate the Alignment Style Editor, and use it to define a new alignment style for the road centrelines.
  • Parametric Design lends it’s self to complex intersection design, and we explore the available techniques by laying out and grading kerb returns and intersection widening.


  • The day starts by reviewing the techniques covered in Day 1, then goes on to use parametric elements for the vertical design for a land development.
  • The implications of a change to the grading of the main road are discussed, then the vertical design is redone using ‘Computators’ where the vertical elements interrelate.
  • The use of Computators in horizontal design is explored by designing a roundabout.
  • All elements in the roundabout are computated, so that it’s location can be adjusted, or have it’s size changed, and all geometry will be correct.
  • Once participants have a gained a good step by step knowledge of the process for computator design, we use the automated tools in 12d Model to create and grade kerb returns, then use an Intersection Component to generate the geometry for a major intersection.
  • Both the kerb return and the Intersection Component are manually edited and their method of construction using computators is investigated.
  • Throughout the course you will be given exercises to practice the skills that you have learnt, and reinforce the design techniques.