Road network basics

Transportation models require a road network, and a very simple road network is depicted in the figure below. The forest data set consists of 6 blocks (the polygons). The road network data set consist of five landings (the red dots), four roads (the blue lines) and one processing facility (the brown mill). The road model also identifies the landings that will be associated with each feature: Block.1 is connected to landing 2, Block.2 is connected to landing 3, Block.4 and Block.5 with landing 4, Block.3 and Block.6 with landing 5, and the mill with landing 1. See Road Networks for a more complete explanation of the road network model.

In this very simple transportation model wood harvested in each block and is forwarded to the closest landing, loaded on to trucks, and transported to the mill. In the following sections of this chapter we will show how to use specialized route accounts to identify the harvest volume to be shipped to the mill, the products that each mill accepts, and how to add up the construction, transportation, and maintenance costs required to implement the road network that gets the wood to the mills. From this simple formulation we will explain how more complex models may be developed.

The road network data set must be loaded in to Patchworks in order be able to set up transportation model accounts. See the section the section called “Add route account code to the PIN file” for information about setting up the PIN file correctly.