Three performance areas can be singled out in the human-machine system as key factors for improving active safety. (1) The vehicle should provide good response and controllability in relation to the driver's operational inputs. (2) Vehicle behavior should be highly stable and free of any sudden changes. (3) There should be a sufficient flow of information from the vehicle to the driver to assure accurate recognition of present vehicle conditions and good predictability of subsequent vehicle behavior. Based on this framework, an analysis was made of the torque split between the right and left wheels, an optimum traction control method was devised for improving the performance areas noted above. That method was incorporated into an electronically controlled limited slip differential system. Vehicle tests conducted with the system confirmed that it significantly improves vehicle dynamics, including traction, steerability and braking stability while cornering.