Given the ever-growing distribution of new in-vehicle information systems, the assessment of their distraction potential becomes an important issue. An accurate estimation of their impact on driver behaviour should be made in the early stages of product development. Several easy-to-use methods can be used to make this early estimate, one of them being the lane change task (LCT). As this task is being considered as an ISO standard, questions about factors that might influence or even distort the results obtained through this procedure arise. One problem, which is the focus of this paper, is the possible occurrence of learning effects. We report the results of two experiments that show that participants' performance improves significantly after just one LCT encounter, and that this improvement is rather stable.