Moving with the traffic is one factor. Another factor is the speed that the roads are designed to handle. While the former is probably the most significant fact

Moving with the traffic is one factor. Another factor is the speed that the roads are designed to handle. While the former is probably the most significant factor when it comes to safety, there is little doubt in my mind that traffic fatalities would go down if everyone moved with the traffic at the speed limit. As for people adapting their speeds based upon what's safe and what's not, sometimes it happens and sometimes it doesn't. The joke around here is that people forget how to drive during the first snowfall. Not forget how to drive in the snow. Forget how to drive altogether. Why? Because people aren't adapting their speed. Likewise, people often drive at high speeds on winding roads. People often drive with sole consideration to the road, without any consideration to what surrounds it (e.g. schools, hospitals, pedestrians, cyclists, lane ways, entrances to parking lots, etc.). Speed limits exist for a reason. Yes, sometimes bad decisions are made by stupid people when creating those speed limits. On the other hand, those stupid people probably know more about traffic safety than someone who thinks they have the right to endanger people by driving over the speed limit.