<p>Urban commuter rail systems are vital for sustainable mobility in developing cities, yet most studies on service quality in India focus on metropolitan areas, leaving Tier-II cities understudied. This paper evaluates commuter satisfaction and service efficiency of Patna’s rail network using a robust mixed-method approach. Primary data were collected from 500 regular commuters across four major stations (Patna Junction, Rajendra Nagar Terminal, Danapur, and Fatuha Junction) and six halt stations (Banka Ghat, Deedarganj, Patna Saheb, Gulzarbagh, Sachiwalaya Halt, and Phulwari Sharif) through a structured questionnaire survey. Importance–Performance Analysis (IPA) was applied to identify service attributes requiring improvement, and ordinal logistic regression was employed to assess the role of socio-demographic factors in shaping satisfaction. The results reveal that affordability and safety are highly valued but underperforming, while ticketing efficiency and seating availability are also critical areas of concern. Regression findings confirm that age and travel frequency significantly influence commuter satisfaction, underscoring the importance of demographic variation in service evaluation. The contributions of this research are threefold. First, it provides empirical evidence from a Tier-II Indian city, a context rarely studied in commuter rail literature. Second, it advances methodological rigor by combining IPA with regression analysis, moving beyond descriptive approaches. Third, it offers practical guidance for policymakers and railway authorities to improve affordability, punctuality, and safety in commuter rail, thereby promoting inclusive and sustainable mobility. By articulating these contributions, the study enhances both academic debate and policy relevance, while demonstrating a replicable framework for evaluating service quality in developing urban contexts.</p>