There are approximately 100 variable message signs (VMS) distributed throughout the Swiss national road network. These are information display panels on which various texts, signals and pictograms can be displayed depending on the traffic situation and requirements. During off-peak times, the time is displayed as standard.A few years ago, various texts were designed to alert motorists to safety-relevant behaviour (e.g. "Tired? Take a break" or "If you drink, don't drive"). Since then, these campaign messages have been regularly displayed on the VMS.Currently (2020), the list of campaign texts comprises about 20 messages, which are available in three national languages. Due to increased reactions from motorists, it is assumed that not all campaign texts are equally well received and understood.So far, it has not been comprehensively clarified empirically in Switzerland whether there is a potential for improvement with regard to the campaign messages and the switching rhythm. These uncertainties are to be resolved with the help of the present project and concrete recommendations and possible suggestions for improvement are to be made on the basis of surveys and driving simulator tests.