Abstract
The effects of local and frequently updated information of adverse weather (including ice and snow) and road conditions on driver behaviour were studied in Finland. Information was transmitted by variable message signs (VMS). These consisted of slippery road condition signs, minimum headway signs, temperature displays and speed limits. The signs were shown to improve traffic safety. Drivers responded by reducing speed and increasing headways. Lowered speed limits due to poor weather and road conditions were generally well accepted. The use of fibre-optic signs was recommended for weather-controlled applications.