Radi(c)al departures Comparing conventional octolinear versus concentric circles schematic maps for the Berlin U-Bahn/S-Bahn networks using objective and subjective measures of effectiveness

An experiment is reported in which two designs of Berlin U-/S-Bahn network maps were compared for usability. One was conventional, based on standard schematic design rules used worldwide: Straight lines with tightly radiused corners, and only horizontal, vertical, or 45° diagonal angles permitted. The other was a novel concept, based on concentric circles and spokes radiating from a central point. The former has the benefit of simple line trajectories, the latter potentially has the benefit of a coherent overall appearance. The experiment investigated both an objective performance measure (time required to plan complex journeys) and a variety of subjective measures (choice between maps, ratings of statements associated with usability, direct ratings of usability). All subjects planned journeys using both designs. Overall, performance was worse for the concentric circles map, and it received poor ratings. However, in line with previous research, objective and subjective measures were dissociated. For example, many subjects expressed a preference for the design that was not the best for them in terms of objective performance.