Joint impacts of Bus Rapid Transit and urban form on vehicle ownership: New evidence from a quasi-longitudinal analysis in Bogotá, Colombia

Bus Rapid Transit (BRT) has become popular as a means to provide non-automobile-based mobility and alleviate the impacts of rising traffic congestion in cities around the world. However, there is little empirical evidence supporting BRT’s potential to meet these objectives. This research improves our knowledge of BRT’s potential as an alternative to vehicle ownership at the household level and provides new evidence of the role of urban form in supporting transit investment. We use a difference-in-differences research design to examine the change in vehicle ownership from before to after implementation of Bogotá, Colombia’s TransMilenio BRT system. Our results indicate access to TransMilenio’s main trunk system is significantly and negatively associated with vehicle ownership for higher wealth households. Among lower wealth households, access to the trunk system and the complementary feeder system (designed to bring passengers from peripheral neighborhoods into the main trunk system) are both associated with an unexpected increase in the odds of vehicle ownership; however, that increase appears to be reversed in neighborhoods where the built environment supports transit and non-motorized travel. This research contributes a methodology for joint analysis of urban form and transit availability on vehicle ownership, and demonstrates that urban form and transit access can have a synergistic effect. Neglecting this synergy would be a missed opportunity to further leverage the benefits of BRT investments. Our findings also suggest that, in the case of Bogotá, the vehicle ownership impacts of BRT investment may not accrue to lower income households unless that investment is coordinated with policies to promote supportive urban form.