Improving Angular Resolution in Visualizations of Geographic Networks

Abstract

In visualizations of large-scale transportation and communications networks, node coordinates are usually fixed to preserve the underlying geography, while links are represented as geodesics for simplicity. This often leads to severe readability problems due to poor angular resolution, i.e. small angles formed by lines converging in a node. We present a new method using automatically routed cubic curves that both preserves node coordinates and eliminates the resolution problem. The approach is applied to representations in the plane and on the sphere, showing European train connections and Internet traffic, respectively.