When Does the Driver Workload Reaches Its Limits ?

Since few years, the tendency is in the increasing of in-vehicle system number. These systems can be more or less useful for the driving but before being integrated in a wide range of vehicle, the compatibility with the driving task must be discussed. A previous study, using on-line subjective workload assessment had shown the limits of such approach. This paper describes a second experiment which goal is the design of an workload indicator based on objective and subjective measures by the study of the driving performance when the driver become overloaded. After a review of the different second tasks used to evaluate the impact of cell phone on driving and the different performance indicators used, the set up of the experiment will be discussed