The growth of literature in the field of quality of service in the public transport (PT) sector shows increasing concern for a better understanding of the factors affecting service quality (SQ) in PT organizations and companies. A large variety of approaches to SQ have been developed in recent years owing to the complexity of the concept; the broad range of attributes required to evaluate SQ; and the imprecision, subjectivity, and heterogeneous nature of the data used to analyze it. Most of these approaches are based on customer satisfaction surveys. This paper seeks to summarize the evolution of research and current thinking as it relates to the different methodological approaches for SQ evaluation in the PT sector over the years and to provide a discussion of future directions.