Apart from the best-practice cases where public administration has been able to manage the transit service network and implement a strong regulation system, in the majority of Latin American cities public urban transport is supplied by a great number of quasi-artisan operators in an almost deregulated context. The private providers secure an intense but essentially deficient and unbalanced supply. With the growth of the cities and thus, increasing trvel distances, the deficiency of the public transport system becomes more problematic, especially for the lower income groups living on the outskirts. Moreover, the extension of the service, supplied in an increasing number of small vehicles competing on the streets, effects the worsening of traffic congestion and pollution. These problems arise as soon as the public authorities are not able to regulate the transport industry, not to mention to provide an efficient transport system by themselves. The lack of technical skills to plan, regulate and control the services but also weak political motivation are the primary obstacles to solve the poblem. The political and social costs of major regulatory changes often discourage politicans empowered, looking for more vote effective activities and measures. In order to implement an efficient regulation system, a stepwise, adaptive procedure has to be applied, securing over years significant improvements and the maturing of the transport industry.