A braking system for vehicles having a master cylinder, and at least one braking device. The master cylinder has a first and a second output circuit, containing the same brake fluid. The first output circuit is intercepted by a first control valve fluidically connected to a braking simulator and to the at least one braking device so as to alternately connect the first output circuit to the braking simulator or to the at least one braking device for its actuation. The second output circuit is fluidically connected to the at least one braking device for its actuation, an automatic hydraulic actuation unit operatively connected to the master cylinder by a hydraulic actuation circuit containing an actuation fluid distinct from the brake fluid and fluidically separated from this. And, at least a processing and control unit of the system that supervises the operation of the braking systems.