Roberts M – SEARCHING FOR SHAPE 2024

Description

Maxwell J. Roberts’ article examines the use of circles to represent orbital lines on transit maps as a means to simplify route comprehension, surveying historical and modern designs and his own work. He shows early successful hybrids—most notably the 1931 Berlin S‑Bahn map—that rendered the Ringbahn as a perfect circle integrated with octolinear straight lines, and explains why integration matters: straight segments should meet curves tangentially or perpendicularly to avoid visual conflict. He contrasts this with less successful examples, such as a 1936 Paris lottery map that used a circle but left chaotic inner angles, and 1970s Moscow diagrams that were striking yet suffered congested station names. With computer tools, new hybrid experiments emerged, including Rafa Sañudo’s 2007 Madrid proposal using all circular arcs. Roberts emphasizes that circles can anchor schematic clarity only if the rest of the network follows compatible, orderly rules; challenges remain in label placement, line divergence, and preserving usability when mixing geometries.