Many drivers exceed the posted speed limits. But even if they keep to the posted speed limit, their speed may be inappropriate for the prevailing traffic, road or weather conditions. Objective data on the prevalence of inappropriate speed is difficult to obtain. One reason is that we do not know enough about the appropriate speed for specific conditions.
However, the vast majority of the drivers do adapt their speed to the actual conditions. For example, in rainy conditions the average speed is lower than when it is dry. At the same time the accident risk is higher during rain . So, it must be concluded that the speed adaptation is insufficient and the speed still inappropriate for rainy conditions and other adverse conditions