With the dynamic limit of 80 km/h, there was a further reduction of 3.4 km/h. In those situations when the lower limit was accompanied by the slippery road warning sign, the prevailing weather and road surface conditions reduced traffic speeds by 9.3 km/h with the combination of lower limit and slippery road warning bringing about a further reduction of 1.8 km/h. There was also an effect that the signs reduced speeds on adjacent road sections.