The connectivity and dependency between various connected locations has become stronger as the rate of urbanization and economic expansion has accelerated. Transport has played a critical role in promoting the flow of economic benefits and growth across linked geographical areas since its origin. Therefore, the purpose of this paper was to provide deeper insights into the relationship between service quality and client satisfaction by exploring the mediating and moderating role of service quality and quality pursuer on client satisfaction. The research used quantitative approaches and employed a non-probability sampling technique. The 240 samples were analysed using Partial Least Squares Structural Equation Modelling (PLS-SEM). The findings show that there is a positive relationship between, assurance, responsiveness, convenience, and service quality. Conversely, findings show an insignificant relationship between empathy and service quality. Findings specify that service quality mediate the association between assurance, responsiveness, convenience, and client satisfaction. Nevertheless, the study observed an insignificant mediation effect of service quality on the linkage between empathy and customer satisfaction. The findings specify that quality pursuers have a significant moderating effect on the relationship between service quality and client satisfaction. As a result, the findings of this present research give useful information for improving client satisfaction and the role of long-term viability of the high-speed rail business in the national economy. This research offers valuable insights for transportation agencies by examining the link between service quality attributes and passengers’ intentions to reuse services, aiming to enhance the provided service, boost ridership, and support the implementation of sustainable transportation policies. The study recognizes certain limitations, such as the restricted sample size and the diverse characteristics of high-speed rail passengers, which may skew the understanding of how service quality affects customer satisfaction and subsequent behaviors. Our results suggest that satisfaction levels among passengers could differ based on the specific routes taken and the types of seating arrangements offered. Consequently, authorities should priorities service quality and its four important characteristics.