Roberts M, Newton, Lagattolla, Hughes and Hasler – OBJECTIVE VERSUS SUBJECTIVE MEASURES OF PARIS METRO MAP USABILITY 2013

Description

This paper evaluates whether strict octolinear metro schematics are optimal by comparing the official RATP Paris map with an “all-curves” Bézier-smoothed design across three usability experiments. In the main study (N=120) and two replications (N=40; N=32 with a 40 s deadline), participants planned difficult multi-interchange journeys from a single map. Objective measures were planning time, invalid routes, and estimated journey duration; subjective usability and map preference were also recorded. The all-curves map yielded consistently faster planning and fewer invalid routes (moderate–large effect sizes, e.g. d≈0.48–1.12), while estimated journey durations were similar between maps and some route-specific effects varied. Subjective ratings and map choice did not reliably predict objective performance—preferences tracked perceived usability more than actual outcomes. Analysis implicated visual layout factors (kinks, line elongation, orbital clarity) in route selection. Authors conclude octolinearity is not universally optimal, recommend tailoring linearity to network properties, automated multi-criteria map generation, and further work on user expertise and artificial networks.