Passengers information in public transport and privacy: Can anonymous tickets prevent tracking?

•The paper focuses on the privacy issues related to the management of sensitive information gathered by transportation companies.•We discuss the use of e-tickets, with a focus on customers’ privacy.•We provide a case study based on anonymous 10-ride tickets.•We propose a number of recommendations for the design and management of public transport information systems, aimed at preserving the users’ privacy.

Modern public transportation companies often record large amounts of information. Privacy can be safeguarded by discarding nominal tickets, or introducing anonymization techniques. But is anonymity at all possible when everything is recorded? In this paper we discuss travel information management in the public transport scenario and we present a revealing case study (relative to the city of Cesena, Italy), showing that even anonymous 10-ride bus tickets may betray a user's privacy expectations. We also propose a number of recommendations for the design and management of public transport information systems, aimed at preserving the users’ privacy, while retaining the useful analysis features enabled by the e-ticketing technology.