Individual and collective public transportation of passengers has been transformed within the law. It has gone from being a public service regulated and guaranteed by administrative law, to being considered, subsequently, as a fundamental right, and as to this day an essential fundamental right. The branches of classical law, such as administrative law and constitutional law, have been guarantors of its efficient provision. At this time the evolution of the service, the needs of citizens, the expansion of cities, the new technologies, the environmental protection and urban challenges generate greater hurdles which are the ones addressed by the Competition Law, Market Law and the Right to the City branches. This work reviews the background, the notions of transportation as a public service, its evolution and poses the challenging and multifaceted character of this phenomenon, as well as the need to act in a coordinated manner between the branches of law to ensure its efficient compliance.