A statistical analysis framework for bus reliability evaluation based on AVL data: A case study of Qazvin, Iran

Reliability is a fundamental factor in the operation of bus transportation systems for the reason that it signifies a straight indicator of the quality of service and operator’s costs. Todays, the application of GPS technology in bus systems provides big data availability, though it brings the difficulties of data preprocessing in a methodical approach. In this study, the principal component analysis is utilized to systematically assess the reliability indicators based on automatic vehicle location (AVL) data. In addition, the significant reliability indicators affecting the bus reliability are identified using a statistical analysis framework. The proposed bus reliability assessment framework can be applied to each bus route or a complete network. The proposed methodology has been validated using computational experiments on real-world AVL datasets extracted from the bus system in Qazvin, Iran. The analysis indicates that 1) on-time performance, 2) headway regularity, 3) standard deviation of the travel time of the buses, and 4) 50th percentile travel time are key indicators the reliability of bus services. The potential of the proposed methodology is discussed to provide insights for bus operators. Using the proposed approach in the article, the desirable reliability status of bus lines is identifiable from the point of view of key stakeholders, and the ways to improve reliability can be more clearly defined.