Virpi Anttila, Juha Luoma and Pirkko Rämä 1 Visual demand of bilingual message signs displaying alternating text messages Virpi Anttila*, Juha Luoma, Pirkko Rämä Technical Research Centre of Finland, P.O. Box 1902, FIN-02044 VTT, Finland *Corresponding author Tel.: 00 358 9 456 4517; fax: 00 358 9 464 850, e-mail:
[email protected]. Abstract This field study was designed to compare the visual demand of variable message signs (VMS). Specifically, three VMS types were evaluated: a sign displaying a message alternately in Finnish and Swedish (2.0 s in each language), a sign displaying the same messages simultaneously, and a sign displaying air and road surface temperatures in Finnish. The data was collected by recording the eye movements of 38 drivers during highway driving. The main results suggested that the sign displaying alternating bilingual messages was no more demanding than the VMS displaying the same messages simultaneously. However, this conclusion is limited to those specific signs and conditions, and more research is needed for related applications in various conditions. The results further suggested that VMSs involving effective technologies might be rather demanding in comparison to the fixed signs. 1. Introduction In December 1997, the Finnish National Road Administration (Finnra) started testing bilingual variable message signs (VMS). The text message module displays text messages alternating between Finnish and Swedish. There is a clear economic advantage in using one sign showing different languages in turn, instead of constructing separate signs for each language when messages have more than 10 characters. It is possible, however, that alternating bilingual messages are more difficult to read and understand than the alternative of a separate message location dedicated to each language.