Criteria for driver impairment

Most traffic accidents can be attributed to driver impairment, e.g. inattention, fatigue, intoxication, etc. It is now technically feasible to monitor and diagnose driver behaviour with respect to impairment with the aid of a limited number of in-vehicle sensors. However, a valid framework for the evaluation of driver impairment is still lacking. To provide an acceptable definition of driver impairment, a method to assess absolute and relative criteria was proposed to fulfil the paradoxical goal of defining impaired driving which is consistent yet adaptable to interindividual differences.