What Makes a Good Flow Map?
Whether radial, network or distributive all good flow maps should have the following characteristics and components as explained by Doantam Phan et al. in their paper, “Flow Map Layout”:
- Intelligent Distortion: Some flow maps feature distortion to show the movement of goods. Therefore it is important that any intended distortion not change the meaning of the map.
- Merging of Edges that Share Destinations: If there are many lines going to the same destination it is important that their edges be combined to reduce map clutter.
- Intelligent Edge Routing: In some cases branches or lines on flow maps will route themselves through the center of the map. This can obscure the other lines so they can be routed to the edge of the map so that all of the data can be easily seen.
- Layering and Branching Structure: Some flow maps have a common set of nodes. In these cases layering of their lines works well to reduce map clutter.
- Linear or Logarithmic Display Widths: Flow maps can use both linear and logarithmic display widths. It is important to choose the correct one to best show the data.