Physiological measures in road safety studies

‘Human factors’ in road safety can be analyzed at the level of: 1) social behavior of the driver and the interactions between traffic participants, 2) single driver performance i.e. the correctness of his actions and the speed of their execution, 3) brain processes underlying the elaboration and execution of these actions. This mini-review addresses the third level. The paper presents methods and measurements of physiological variables that reflect processes relevant to car driving. The stress, the level of alertness and the mental workload are considered. Typical methods, based on cardiac, respiratory, oculomotor, electroencephalographic and evoked potential recordings are presented. These are supplemented with less frequently used, but potentially important indicators such as galvanic skin responses or facial expression. Applications of these measures in road safety studies, results already obtained and perspectives for future are briefly discussed. In many cases, car driver’s data were either unsatisfactory or simply nonexistent. Therefore, the car driver’s and aircraft pilot’s data had to be used jointly.