A Field Trial of Vehicle Grip Compared to RWS Data

Driving safety is a key concern for road authorities. Other than the weather, one of the most interesting factors which affects safety is a vehicle’s grip, i.e. the friction between a vehicle’s tires and the road surface. Together with the Finnish Road Administration Vaisala conducted a field trial in Southern Finland during the winters of 1999-2000 and 2000-2001 to study which measurement results best indicated a vehicle’s grip. In the trial, the measurements from the Vaisala ROSA Road Weather Station (RWS) were compared with independent human observations of vehicle grip.