Substitution or Complementarity

Abstract

The effects of a real-time bus information system, Chicago Transit Authority (CTA) Bus Tracker, on the ridership of the CTA transit rail system in Chicago, Illinois, are examined with panel data on monthly average weekday ridership at each transit train station in the entire CTA system from January 2005 through December 2010. Other factors that might contribute to changes in CTA rail ridership (e.g., socioeconomic situation, transit service, and weather) are controlled. Results of a mixed linear model indicate that Bus Tracker service increases CTA train ridership. This increase might be attributable to the increased intermodal transfer efficiency between CTA buses and trains that results from the real-time bus information provided. Findings suggest that the complementarity effect of providing real-time bus information outweighs its substitution effect on the ridership of a connected transit rail system. Together with the findings from an earlier study (which show that Bus Tracker service helps to increase bus ridership), study results provide empirical evidence in support of the hypothesis that implementation of a real-time transit information system leads to gains in transit ridership.