MINSALT. REDUCTION OF THE SALTED ROAD NETWORK IN KOPPARBERG COUNTY

This study forms a subsidiary project in the major research project Reducing the damage from salt for road maintenance purposes - MINSALT carried on by the Swedish Road Administration and the VTI for several winters. The purpose of the experiment in Kopparberg county is to study the consequences for road users and road maintenance authorities, as well as road user opinion, when the extent of the salted road network is reduced. Over a period of two winters, the salted road network was reduced from 1,450 km to approximately 450 km. The reduction was made mainly where climate and traffic conditions were favourable. The greatest reduction, measured in km, was achieved by eliminating salting of the whole of the low-trafficked road network (category B salted roads.) The high-trafficked salted network (category A salted roads) was reduced to about half its earlier length. The following effects were studied: (1) road condition, (2) variation in traffic flow according to road condition, (3) spot speed, (4) standstills and tailbacks, (5) accidents, (6) road wear, (7) implemented actions and the costs of the road maintenance authority, (8) road user opinion, (9) experience of the road maintenance authority. Follow-up studies show that the experiment has had many effects: in certain cases, the effect has been considerable. (A)