Example: One-way Road Network

In this example, we want to construct a network graph of one-way roads.

The direction is important when defining this network graph.

The end of a one-way street can touch either:

  • The start of another one-way street, or
  • Anywhere on a two-way street

A two-way street can touch either:

  • The start of a one-way street, or
  • Anywhere on a two-way street

Here we will compare two methods of creating this network graph. One using a single complicated action, and another using two simple actions.

Method 1: One Action

In our example below, a one-way road network is constructed using the built in operations add_position and connect_positions.

Although the network graph is constructed successfully, the required action is very complicated.

A screenshot of an action built to define a one-way system.

Example action defining a one-way system

Method 2: Two Simpler Actions

Alternatively, you can add and connect all roads in one action then disconnect any roads not relevant to the one way system in a second action.

An screenshot of the first action in the sequence that adds all of the roads.

First action adds all roads

A screenshot of the second action that removes all roads not relevant to the one way system.

Second action removes roads not relevant to the one way system