Informing drivers about events and their location in Variable Message Signs: effects of words versus pictograms

With advancing road technologies and growing traffic complexity, a major challenge is to inform drivers through clear and concise messages. This study examines how drivers understand Variable Message Signs indicating the location of an event relative to a city. Four message designs were tested, resulting from two crossed factors: the event category was informed by either a word or a pictogram, and the location of the event was indicated by either a word or an arrow. Twenty-four drivers were asked to identify the message as quickly and accurately as possible. Compared to text: (1) for the event, pictograms led to faster (M _pictogram = 6112 ms; M _text = 6338 ms) and more accurate (R _pictogram = 1.00; R _text = 0.99) responses; (2) for the location, the arrow resulted in worse accuracy (R _arrow = 0.98; R _text = 0.99) and response time (M _arrow = 6261 ms; M _text = 6189 ms). Text-pictogram combinations may constitute a functional strategy toward the harmonization and internationalization of road signage, although the effectiveness of specific combinations likely depends on how clearly each element conveys its meaning.