Radial flow map showing the mail volumes on airplanes in the US.

Flow maps demonstrates flows within networks, and lines of varying widths are used to visualize different magnitudes of flow.

The map to the left is a radial flow map. Radial flowmaps show flows like airline traffic between destinations. For this part of the lab, Federal Aviation Administration's (FAA) airline traffic data was used. 

Lines of different widths tells us that mail volumes on airlines are greatest from Alaska to various points, as well as into some of the US Postal Service's Network Distribution Centers (NDCs).

Here, traffic flow in Oregon has been visualized using numeric values for the average annual daily traffic, collected by Oregon Department of Transportation. The map is symbolized so that the highway with the greatest traffic flow stands out. Other roads are also shown, with varying width of the lines in accordance to the traffic flows.

Flow map showing the traffic flow in Oregon.