This paper takes a critical look at the public transport reform implemented in the city of Santiago (Transantiago) in February 2007. It argues that design (and not implementation) failures on at least two levels were the fundamental cause of its severe problems: (a) in the centralized modeling of inadequate and extremely rigid routes for a city like Santiago where patterns change significantly; (b) in the construction of rigid contracts lacking an incentive structure sufficient to ensure a good quality of service. The study also looks at the institutional architecture of decision-making in the reform, concluding that there was an important vacuum in that architecture. According to the paper, the institutional framework created problems in coordination, technical competencies and a dilution of responsibilities. More importantly, it confirms that reforms of a scope like Transantiago can be implemented in Chile at the discretion of the Executive Branch, evading the necessary institutional weights and counterweights that raise alarms.