TRAFFIC AND TRANSPORT PSYCHOLOGY : THEORY AND APPLICATION. CHAPTER 18. SUBJECTIVE EVALUATION OF THE MENTAL WORKLOAD IN THE DRIVING CONTEXT

In the near future, the driving task is going to be strongly modified, due to the implementation of telematic systems offering various functions and aiming to assist the driver. The effects of the implementation of these systems are currently under study, and will certainly be under investigation for some time, according to the novelty and the complexity of this new situation and the road safety issue. According to the results from two experiments (navigation/guidance system evaluation and hands-free car phone evaluation), the Driving Load Activity Index (DALI) seems to be a tool that enables the gathering of informative data about the mental workload for the driver. As for the NASA TLX, the principle is to investigate the mental load experienced subjectively by the drivers in various conditions. The ability to identify factors that take into account the specificity of the driving task is efficient and useful for the researcher. For these two experiments, results obtained from the DALI scores were confirmed by other data (drivers' comments, some objective data, expertises...), leading to the conclusion that this tool is an efficient one for research purposes. For the covering abstract see IRRD 896859.