Critical situations, which can arise at car's motion and should be prevented by its safety systems, are subdivided into two levels. The micro-level is connected directly to wheel-road-interaction, and the macro-level with the car's behavior. For creation of effective control philosophy of the systems of active safety a new approach for description of tire grip - wheel slip – dependencies is offered that gives the basic performance for an evaluation of critical situations. For authentic recognition of critical situations the system of active safety should be constructed on intelligent principles with parallel information channels and with possibility of self-configuration.