Bus Ridership and Service Reliability: The Case of Public Transportation in Western Massachusetts

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The linkage between crowding and service quality in transit systems is an issue of major concern among city planners, transportation managers and passengers. This article analyzes over 1.3 million readings on daily bus service running every 15 minutes across eleven routes in Western Massachusetts to investigate the relationship between ridership and the reliability of a bus service. Results indicate that an additional unit increase in the number of passengers results in a 0.9% reduction in the reliability of bus services. Estimates suggest that high volumes of bus ridership cause a significant increase in the variance of bus service reliability. Results also show that the bus service is more reliable during the weekends and in the summer session when relatively fewer students need public transportation. These findings have policy implications for quantifying the economic cost of unreliable bus services associated with large volumes of passengers.