This paper presents a brief description of the evolution of Pico y Placa (vehicular restriction) in Medellin, a measure to restrict the vehicular circulation during peak hours. An analysis is exposed based on previous studies before its implementation (2004). This article also provides a comparison within the results of subsequent studies (2005 to 2008) with and without restriction. In addition, presents and analyzes its limitations in the long term and the impact on emissions; finally, a set of recommendations are presented to improve and evaluate the vehicular restriction in the future.