The present work studies the effects of implementing passive and active Transit Signal Priority (TSP) strategies upon and specific mass Public Transportation system. The analysis was carryout from the results of micro-simulations modelled in the Aimsun, loaded with real information of the traffic demand, BRT system and control characteristics, encounter for the Bus Rapid Transit (BRT) system of the city of Santiago de Cali , Colombia. The scenarios considered for the different TSP strategies contemplates different amount of BRT lines prioritized, different types of TSP and different intersections in which the prioritized vehicles can be detected. By an evaluation of the response of the network to the different scenarios was possible to conclude that the implementation of any TSP strategy requires a careful study on the impacts, not only in the Mass Public Transport system, but also in the non-prioritized traffic; as the priorization of a particular vehicle constrains the flow of other traffic that, depending on the particular configuration of manoeuvrers and control, can lead to an adverse result..