Seasonal speed limits in Finland, in which speed limits have been reduced from 100 to 80 km/h during the winter, have had a positive effect on road safety. Two studies were conducted by VTT to evaluate the current practice of applying wintertime speed limits on rural main roads and to estimate the effects of reducing the speed limits of long trailer lorries from 80 to 70 km/h during the winter. In the first study, a comprehensive database was obtained to evaluate the speed limits for a specific vehicle fleet or road group. Data were obtained from the Road Administration's road and accident database and automatic traffic measurement points and from the Finnish Motor Insurers' Centre's accident study teams. The data showed the benefits of the reduced speed limits in wintertime. Most of road freight in Finland is transported in full trailers (at least 22m long articulated trucks), which are more unstable than semi-trailer trucks. Wintertime speed reductions would reduce the number of injury and fatal accidents. The Ministry of Transport and Communications increased the number of road sections with a wintertime speed limit of 80 km/h and limited the maximum speed to 70 km/h on some roads.
Abstract