False correlation.<p>Yes, speed is such a significant factor in the severity of accidents that it can be isolated as a sole point of focus. That does not hold true for the frequency of occurrence.<p>Increased speed does increase the probability of an accident but not so significantly that it can be isolated apart from other contributing factors. That is significant because as other factors contribute more to the probability of accident controlling for those factors reduces both the number of accidents and thus the number of accident fatalities.<p>Ignoring this logic results in bias and thus an incomplete or faulty solution. People always want to isolate for controlling for speed because of over simplification, or rather a hasty conclusion.