Spiral Plot Analysis of Variation in Perceptions of Urban Public Transport Performance Between International Cities

Document Type

Journal Article

Publication Date


Subject Area

place - australasia, place - europe, place - north america, place - urban, ridership - perceptions, planning - service level, planning - service quality, planning - personal safety/crime, operations - performance, operations - frequency


spiral plot analysis (SPA), importance–performance analysis (IPA), customer perceptions, transit service attributes


This paper presents a method for comparing perceptions of transit service attributes across different customer groups. It compares customer perceptions across 22 service attributes in nine major world cities (Toronto, Ontario, Canada; New York City; San Francisco, California; Boston, Massachusetts; Sydney, Brisbane, Perth, and Melbourne, Australia; and London) by using an importance–performance analysis (IPA) framework. This paper proposes a new approach to displaying results of IPA, a spiral plot analysis (SPA), to highlight similarities and differences across a large range of attributes between disaggregate groups in the case cities. Results showed a general consistency between cities in the importance of service attributes. Greater variation in performance of attributes was found. The IPA suggested the average target area (high importance–low performance) attributes for the nine cities were (in order): “feeling safe traveling on public transport at night,” “the ability of operators to deal with service disruptions quickly,” “unexpected service disruptions don’t happen very often,” “quality of service on public transport,” “public transport operating frequently,” and “having public transport travel options available when and where I need them.” Results stressed how important unplanned disruptions were to passengers in all cities. Results for some individual cities were slightly different, although these attributes were critical for all. The SPA method more concisely illustrated similarities and differences between cities as well as highlighted which attribute scores were more important to customers. The SPA illustrated that Melbourne had some of the largest gaps between expectations and performance, whereas New York City tended to have the smallest. Areas for future research are discussed.


Permission to publish the abstract has been given by Transportation Research Board, Washington, copyright remains with them.