The purpose of this research is to evaluate the quality of service offered by the BRT (Bus Rapid Transit) System in the City of Barranquilla, Colombia. A model is designed and tested to explore critical quality factors that stakeholders consider important to predict passenger satisfaction with the service. The study aims at identifying the quality factors that could help to improving the existing transportation service-related research in emerging economies such as Colombia (a country where the growth of the mass transportation sector is expected following significant investments made by the government). This research shows that the four independent variables – information availability, safety on buses, ergonomics, and system accessibility have a positive and significant predictive power of the quality of the service.