An instrumented vehicle was used for real-time recording of drivers physiological characteristics (galvanic skin responses, heart rate and muscle activity), steering and braking behavior and vehicle response (speed, distance travelled and triaxial accelerations). Using multiple regression techniques it is shown that for the inexperienced group, road-traffic situations involving the use of the brake explain most of the variance in the physiological measures. Similarly, the steering response was the most important variable for the experienced group. Control skills develop rapidly whereas the discrepancies in physiological responses indicate the relatively slow development of skills necessary for collecting the relevant information