Located on the southern coast of Finland, the Uusimaa road district started to reduce the amount of salt applied to roads to prevent slippery conditions on roads located in areas with ridges. The latter are sand and gravel formations that are highly permeable to water. The combined length of the roads selected for the salt reduction experiment during the first winter was 162 km. The purpose of the experiment was to determine what the chances are of reducing the application of salt as a means to combating slippery conditions. Simultaneously, the surface friction requirement for the roads was decreased from 0.30 to 0.25. The aim is to prevent a rise in the chlorine concentration of groundwater. Natural chlorine levels in Finland in typical groundwater area formations are less then 10 mg/l. On the roads used for the experiment, the effects of reduced salt application on groundwaters have been studied by measuring the chlorine concentrations over a five-year period. There are a total of 52 water pumping stations which have to be monitored. During the first year of the experiment, the chlorine concentration in the groundwater has decreased by an average of 1.26 mgt/l. On the roads used for the experiment the amount of salt applied is reduced by approximately 40 % compared to the average over the previous winters. An average of 5.8 tons of salt per road kilometre is being applied. No changes at all are discernible in the number of accidents compared to the years used as the control years for the experiment. Changes in speeds are extremely slight. In conjunction with the experiment, feedback was gathered from the road users using the roads featured in the experiment. There is nothing that could directly be linked to the experiment in this feedback. The opinions of road users were also surveyed using a questionnaire in March 2001. The majority felt that the amount of salt ought to be reduced. Some corresponding motorway roads were included in the experiment during the 2000-2001 winter.