There is provided a system for the measuring of the BAC and/or possible existence of illegal active substances in a driver (4) of a vehicle, the system characterized in that it comprises: a first portable device (1) which comprises at least one sensor for detecting the BAC and/or other illegal active substances of said driver (4); and a second device (2) fixedly mounted on the vehicle and which it is interfaced with said first portable device (1) to receive/send one or more electrical signals to a control unit, the latter being mounted on said vehicle; the arrangement being such that said electrical signals from said second device (2) are related to the detected/sensed values of BAC and/or other illegal active substances and coming from said first device (1), and said control unit being adapted to control the management of the whole vehicle consequently and according to the values of said electrical signals.