Geometry Configurations Managing nodes and using existing nodes

Geometry Configurations Part 4 – Managing nodes and using existing nodes

Technical Note #13

February 2015
By Andreu Tarrida

Managing Nodes

Case A

The new geometry uses some or all of the turns in the base geometry.

This new geometry uses some or all of the turns in the base geometry

After selecting the Nonexistent Here and Existent Only Here objects, you’ll see part of the original node.

Select the Nonexistent Here and Existent Only Here objects

Double-click on the node to access the editor and then create the new turns between base sections and new sections, and also between new sections.

Select the Nonexistent Here and Existent Only Here objects

When using the Connection tool, do not create a turn between two new sections first because it will create a different node. You must involve a base section when creating the first turn.

Connection tool

Case B

The new geometry doesn’t use any turns from the base geometry.

The new geometry doesn't use any turns from the base geometry

After selecting the Nonexistent Here and Existent Only Here objects, you won’t see the original node; however, all or some base sections are involved in the new geometry.

The new geometry doesn't use any turns from the base geometry

Even though the node is not displayed, it still exists, so in order to create the rest of turns you must use either the Connection tool or the Node tool.

If you use the Connection tool, do not create a turn between two new sections first because it will create a different node. You must involve a base section when creating the first turn.

If you use the Connection tool, involve a base section when creating the first turn

If you use the Node tool, make sure that you include a base section in the selection.

If you use the Node tool, include a base section in the selection

Using Existing Nodes

Duplicating objects

In some cases, streets and roads will undergo changes such as number of lanes, direction or lane availability for turns. While these changes wmay not necessarily entail a physical change in the infrastructure, in Aimsun you’ll have to duplicate the sections to code the new Geometry Configuration.

Here are a couple of examples

  1. The new section has a different number of lanes

    Using Existing Nodes in Aimsun Geometry Configurations - The new section has a different number of lanes

  2. The new section is in the opposite direction
    Using Existing Nodes in Aimsun Geometry Configurations - The new section is in the opposite direction
  3. There is a different connection between lanes for the same movement (turn). You’ll have to create a new turn but since there can only be one turn between the same two sections, you’ll have to use new sections to create it.

    Using Existing Nodes in Aimsun Geometry Configurations