Measuring Congressional District Meandering

In recent decades, state legislatures have often drawn U.S. Congressional voting districts that look—to the human eye—to be rather twisted. In this paper, we propose a method to measure how much districts “meander” via a computation of the medial axis of the region. We then compare this to the medial axis of the convex hull of the district to obtain the {\em medial-hull ratio}: a dimensionless quantity that captures the district’s irregularity. We compute this quantity for many example Congressional districts.