The problems with slippery road surfaces are often concentrated in certain locations on the road network (bridges, valleys). This calls for local warning systems such as those based on Variable Message Signs (VMS). Several message types, including both text and pictogram messages are studied. The warnings of slippery road conditions with slippery road (VMS) and following distance recommendations are mostly understood correctly. The drivers did, however, have problems with understanding the different categories of slipperiness (possible slippery and verified slippery). The personnel at the Road Weather Monitoring Centre (RWMC), however, regarded the two categories very useful and even essential for the operation of the system. The comprehension of the following distance recommendations should be improved, for instance with an additional pre-sign or an additional text "recommendation" in the sign.
Samenvatting