1. A driver assistance system, comprising: a driver identity detector to detect the identity of a driver; a peripheral interface to communicatively couple to a transducer input; and one or more logic elements comprising a driver competency engine, configured to: detect the identity of the driver via the identity detector; evaluate the driver's operation of a vehicle according to operational inputs received from the transducer input via the operational sensor interface; build a driver competency profile based at least in part on the evaluating; compute a current risk factor of the form R ⁢ ⁢ F = avg ⁡ ( DS , DG ) K , wherein RF is the risk factor, DS is a normalized speed deviation, DG is a normalized g-force deviation, and K is a constant; and take autonomous or semi-autonomous control of the vehicle or provide user advice responsive to the current risk factor.