Approximately 20% of motor vehicle crashes are caused by sleepiness or fatigue . Therefore, the search of effective countermeasures against driver sleepiness is a key issue in crash prevention. While caffeine, energy drinks and napping have been reported to improve driver alertness, listening to music and cold air have shown too transient and marginal effects in counteracting sleepiness in a driving simulator. However, a recent Swedish survey depicted that drivers use turning on the radio and opening a window more frequently as countermeasure than drinking coffee or stopping for nap. This raises the question if those drivers apply rather ineffective countermeasures or if these countermeasures are more effective when used during actual driving, in contrast to simulated driving. Therefore, this study aimed at assessing the effect of listening to music and opening the window during real driving on the motorway.