Chan, Xu, Chen, Liu and Cheung – DRAWING METRO MAPS IN CONCENTRIC CIRCLES 2022

Description

The paper introduces a designer-in-the-loop tool for creating concentric-circle schematic metro maps that blends automated layout generation with interactive user control. Targeting tensions between manual aesthetics and optimization, it adopts Roberts et al.’s five design categories (simplicity, coherence, balance, topographicity, harmony) and uses constraint equations plus three user parameters—center, polar gridline set, and line importance—to produce multiple feasible layouts for user selection. The algorithm converts station coordinates to polar form, generates candidate grid intersections, and enforces four drawing rules: minimize bends, co-locate or minimally displace transfers by priority, uniformize inter-station spacing, and separate overlapping lines. The method supplies quantitative measures (average bends; circular-grid occupancy; link-length dispersion via 1−Gini; station-average angular distortion) while treating harmony as a visual judgment. A Hong Kong MTR case study shows iterative parameter tuning and trade-offs (radial count, center choice, grid counts) and demonstrates pedagogical value, manual final edits, labeling support, public availability, and avenues for further research on aesthetics and line-importance definitions.