Driver acceptance of weather-controlled road signs and displays

This study was designed to investigate driver acceptance of the weather-controlled road signs and displays on Finland's southern coast where road condition changes are particularly frequent and rapid. There were 36 variable speed limit signs and five variable message displays to warn about hazardous conditions on the 14-km-long experimental road section. Local weather and road surface conditions were monitored automatically from road weather stations; the information gathered was used for determining appropriate speed limit, as well as for controlling variable slippery road signs and temperature displays. Five hundred ninety drivers were interviewed 3, 4, 11, and 13 months after the introduction of this new road section. The results showed that drivers recalled the variable signs very well. Furthermore, 81 percent of the drivers said that the posted speed limit was appropriate, and 95 percent of the drivers stated that the variable speed limits were useful. However, only a relatively small proportion of drivers estimated that the slippery road sign or temperature display influenced their behavior. The main implication of this study is that the concept of the weather-controlled road signs and displays is a promising one. However, objective data will be collected in order to estimate the effects of the weather-controlled road signs and displays on driver behavior and to evaluate the profitability of the system.